Orthopaedics

Chapter: Osteology / Head and Neck; Topic: Joints of the Vertebral Column; Subtopic: Craniovertebral Joints (Atlanto-axial Joint)

Key Definitions & Concepts

• Atlanto-axial Joint (C1-C2): A complex synovial joint consisting of a median pivot joint (between dens and atlas) and two lateral plane joints.

• Atlanto-occipital Joint (C0-C1): The articulation between the occipital condyles and the superior articular facets of the atlas; primarily allows nodding ("Yes" movement).

• Dens (Odontoid Process): The bony projection of the Axis (C2) that acts as the axis of rotation for the Atlas.

• Transverse Ligament of Atlas: The most critical stabilizer of the C1-C2 joint; it holds the dens against the anterior arch of the atlas, protecting the spinal cord.

• Alar Ligaments: Strong bands extending from the sides of the dens to the occipital condyles; they act as "check ligaments" to limit excessive rotation.

• Cruciate Ligament: A cross-shaped structure formed by the Transverse ligament and vertical bands connecting C2 to the occiput.

• Steele’s Rule of Thirds: Describes the space within the ring of the atlas: 1/3 is the dens, 1/3 is the spinal cord, and 1/3 is "safe space" (CSF/fat).

• Atlanto-dental Interval (ADI): The distance between the posterior aspect of the anterior arch of C1 and the anterior aspect of the dens; >3mm in adults implies instability.

• Tectorial Membrane: The superior continuation of the Posterior Longitudinal Ligament (PLL) that covers the dens and cruciate ligament posteriorly.

• Grisel's Syndrome: Non-traumatic atlanto-axial subluxation caused by inflammation in the adjacent pharynx (e.g., post-tonsillectomy).

[Image of Atlanto-axial joint anatomy]

Lead Question - 2016

Movement occuring at atlanto-axial joint?

a) Flexion

b) Bending

c) Rotation

d) Nodding

Explanation: The Atlanto-axial joint is designed specifically to facilitate the rotation of the head. It is classified functionally as a **Pivot (Trochoid) joint**. The ring formed by the anterior arch of the Atlas and the transverse ligament rotates around the vertical pivot of the Dens (Odontoid process) of the Axis. This biomechanics allows for approximately 50% of the cervical spine's total rotation, producing the **"No" gesture** (shaking the head side to side). In contrast, "Nodding" (Flexion/Extension, the "Yes" movement) occurs primarily at the Atlanto-occipital joint. Lateral bending occurs in the lower cervical spine. Therefore, the correct answer is c) Rotation.

1. The median atlanto-axial joint is classified structurally as which type of synovial joint?

a) Plane joint

b) Saddle joint

c) Pivot joint

d) Condyloid joint

Explanation: The articulation between C1 (Atlas) and C2 (Axis) is complex. It consists of three joints: two lateral joints and one median joint. The lateral atlanto-axial joints are plane (gliding) joints. However, the **Median Atlanto-axial joint**, formed between the Dens of the Axis and the osteo-ligamentous ring of the Atlas (anterior arch + transverse ligament), is the classic example of a **Pivot (Trochoid) joint**. This uniaxial joint allows the rotation of the atlas around the dens. The atlanto-occipital joint is condyloid. Therefore, the correct answer is c) Pivot joint.

2. A patient with Rheumatoid Arthritis presents with neck pain and hyperreflexia. An X-ray shows an increased Atlanto-Dental Interval (ADI). This instability is primarily due to the laxity or rupture of the:

a) Alar ligament

b) Transverse ligament of the Atlas

c) Apical ligament

d) Anterior Longitudinal Ligament

Explanation: The **Transverse ligament of the Atlas** is the most vital stabilizer of the craniovertebral junction. It creates a collar behind the dens, preventing it from migrating posteriorly into the spinal canal where it would compress the spinal cord. In inflammatory conditions like Rheumatoid Arthritis, the synovial joints adjacent to this ligament cause pannus formation which erodes and weakens the ligament. Failure of this ligament leads to atlanto-axial instability (subluxation), evidenced by a widened ADI (>3mm in adults, >5mm in children) on flexion views. Therefore, the correct answer is b) Transverse ligament of the Atlas.

3. Which ligament acts as a "check ligament" to limit excessive rotation of the head at the atlanto-axial joint?

a) Transverse ligament

b) Apical ligament

c) Alar ligament

d) Ligamentum flavum

Explanation: While the transverse ligament stabilizes the dens anteroposteriorly, the **Alar ligaments** control rotation. These are strong, thick bands that extend from the dorsolateral surfaces of the tip of the dens to the medial aspects of the occipital condyles. When the head rotates to the right, the left alar ligament becomes taut, checking (limiting) further rotation to preventing damage to the vertebral arteries and spinal cord. They are often referred to clinically as the "Check ligaments" of the spine. Therefore, the correct answer is c) Alar ligament.

4. The "Yes" movement (nodding) of the head occurs primarily at which joint?

a) Median Atlanto-axial joint

b) Lateral Atlanto-axial joint

c) Atlanto-occipital joint

d) C2-C3 joint

Explanation: Different cervical joints are specialized for different motions. The rotation ("No") occurs at C1-C2. The flexion and extension of the head relative to the neck ("Yes" or nodding) occur at the **Atlanto-occipital joint** (C0-C1). This joint is formed by the convex occipital condyles sitting in the concave superior articular facets of the atlas. It is a synovial condyloid (ellipsoid) joint, allowing movement primarily in the sagittal plane (nodding) and slight lateral flexion. Therefore, the correct answer is c) Atlanto-occipital joint.

5. The Vertebral Artery winds behind the lateral mass of the atlas. In this location, it pierces which membrane to enter the vertebral canal?

a) Anterior atlanto-occipital membrane

b) Posterior atlanto-occipital membrane

c) Tectorial membrane

d) Ligamentum nuchae

Explanation: The third part of the Vertebral Artery exits the foramen transversarium of C1 and winds medially behind the lateral mass of the atlas, lying in a groove on the posterior arch. To enter the vertebral canal and skull, it must pierce the **Posterior atlanto-occipital membrane** (which is the homologue of the ligamentum flavum at this level). It then pierces the dura and arachnoid to ascend through the foramen magnum. This complex course makes it vulnerable to injury during C1-C2 rotation or fractures. Therefore, the correct answer is b) Posterior atlanto-occipital membrane.

6. The Tectorial Membrane, which covers the dens and cruciate ligament posteriorly, is the upward continuation of which spinal ligament?

a) Anterior Longitudinal Ligament (ALL)

b) Ligamentum Flavum

c) Posterior Longitudinal Ligament (PLL)

d) Supraspinous Ligament

Explanation: Ligaments of the spinal column change names at the craniovertebral junction. The **Posterior Longitudinal Ligament (PLL)** runs along the posterior aspect of the vertebral bodies, inside the spinal canal. At the level of the Axis (C2), it broadens and continues upwards to attach to the clivus of the occipital bone. This superior extension is called the **Tectorial Membrane**. It covers the odontoid process and the cruciate ligament, separating them from the spinal cord and meninges behind. The ALL becomes the anterior atlanto-occipital membrane. Therefore, the correct answer is c) Posterior Longitudinal Ligament (PLL).

7. According to Steele's Rule of Thirds, the space within the ring of the atlas is equally divided among the dens, the spinal cord, and:

a) Transverse ligament

b) Epidural fat and veins

c) Free space (fluid/safe space)

d) Vertebral arteries

Explanation: The spinal canal at the level of C1 is spacious. **Steele's Rule of Thirds** states that the area of the ring of the atlas is divided roughly into three parts: one-third occupied by the **Dens** (anteriorly), one-third by the **Spinal Cord** (posteriorly), and one-third is **"Space"** (or safe space containing CSF, dura, and epidural tissue). This extra space acts as a safety buffer, allowing some degree of C1-C2 displacement (subluxation) before spinal cord compression occurs. This contrasts with the tight fit in the lower thoracic spine. Therefore, the correct answer is c) Free space (fluid/safe space).

8. A "Jefferson Fracture" is a burst fracture of the Atlas (C1). It typically occurs due to:

a) Hyperextension injury

b) Hyperflexion injury

c) Axial loading (compression)

d) Rotational injury

Explanation: A **Jefferson Fracture** involves the fracture of the anterior and posterior arches of the Atlas (C1), often breaking the ring in four places. The mechanism of injury is a vertical **Axial loading** force applied to the head (e.g., diving into a shallow pool or a heavy object falling on the head). The occipital condyles are driven downwards into the lateral masses of C1, forcing them outward and bursting the ring. If the transverse ligament remains intact, the fracture is considered stable. Hyperextension causes Hangman's fracture (C2). Therefore, the correct answer is c) Axial loading (compression).

9. Which muscle is primarily responsible for the rotation of the head at the atlanto-axial joint?

a) Rectus capitis posterior major

b) Obliquus capitis superior

c) Obliquus capitis inferior

d) Rectus capitis anterior

Explanation: The suboccipital muscles act on the craniovertebral joints. The **Obliquus Capitis Inferior** extends from the spinous process of the Axis (C2) to the transverse process of the Atlas (C1). Its contraction pulls the transverse process of C1 posteriorly, causing the atlas (and the head) to rotate around the dens. It is the only suboccipital muscle that does not attach to the skull, acting exclusively on the C1-C2 joint to produce forceful rotation. Rectus capitis posterior major extends and rotates. Obliquus superior extends/laterally flexes. Therefore, the correct answer is c) Obliquus capitis inferior.

10. The tip of the dens is attached to the anterior margin of the foramen magnum by a thin, rudimentary ligament known as the:

a) Apical ligament

b) Alar ligament

c) Transverse ligament

d) Cruciate ligament

Explanation: The **Apical ligament of the dens** is a thin, slender fibrous cord that extends from the very apex (tip) of the odontoid process to the anterior margin of the foramen magnum (basion). It lies between the anterior atlanto-occipital membrane and the superior band of the cruciate ligament. It is embryologically the remnant of the notochord at the cranial end. While structurally present, it is weak and contributes little to the mechanical stability of the joint compared to the robust Alar and Transverse ligaments. Therefore, the correct answer is a) Apical ligament.

Chapter: Osteology; Topic: Vertebral Column; Subtopic: Regional Characteristics of Vertebrae

Key Definitions & Concepts

• Spinous Process: A bony projection off the posterior (back) of each vertebra; serves as an attachment point for muscles and ligaments.

• Vertebra Prominens (C7): The seventh cervical vertebra, characterized by a long, non-bifid spinous process that is easily palpable at the base of the neck.

• Foramen Transversarium: A hole in the transverse process unique to cervical vertebrae, transmitting the vertebral artery (except C7) and veins.

• Costal Facets: articular surfaces on the body and transverse processes of thoracic vertebrae for articulation with the ribs.

• Mamillary Process: A small tubercle on the posterior edge of the superior articular process, characteristic of lumbar vertebrae.

• Pars Interarticularis: The segment of bone between the superior and inferior articular processes; a common site of stress fracture (Spondylolysis).

• Atlas (C1): The first cervical vertebra; unique for lacking a vertebral body and a spinous process.

• Axis (C2): The second cervical vertebra; characterized by the Dens (Odontoid process) which acts as a pivot for rotation.

• Sacral Hiatus: An opening at the inferior end of the sacrum formed by the failure of the laminae of S5 to fuse; used for caudal epidural anesthesia.

• Intervertebral Foramen: The opening between adjacent vertebrae through which spinal nerves exit.

[Image of Vertebral column regional differences]

Lead Question - 2016

Long spinous process is seen in ?

a) Cervical vertebrae

b) Thoracic Vertebrae

c) Lumbar Vertebrae

d) Sacrum

Explanation: While the C7 vertebra (Vertebra Prominens) has a long spine, the group of vertebrae characteristically defined by long, tapering spinous processes that project obliquely downwards are the Thoracic Vertebrae. In the mid-thoracic region (T5-T8), these spines are almost vertical, overlapping the vertebra below like shingles on a roof. This arrangement limits extension of the thoracic spine. In contrast, typical cervical spines are short and bifid. Lumbar spines are short, thick, and hatchet-shaped (quadrangular) projecting horizontally. The sacral spines are fused to form the median sacral crest. Therefore, the correct answer is b) Thoracic Vertebrae.

1. Which specific feature is the most reliable landmark to identify a vertebra as "Cervical" regardless of whether it is typical or atypical?

a) Bifid spinous process

b) Presence of Foramen Transversarium

c) Small vertebral body

d) Triangular vertebral canal

Explanation: When identifying vertebrae, one looks for unique features. While bifid spines are common in cervical vertebrae, they are not present in C1 (Atlas) or C7. However, the Presence of Foramen Transversarium in the transverse process is the pathognomonic feature of all cervical vertebrae (C1-C7). This foramen transmits the Vertebral Artery (C1-C6) and veins (C1-C7). No other spinal region possesses this foramen. Thoracic vertebrae are identified by costal facets, and lumbar by their massive bodies and lack of facets/foramina. Therefore, the correct answer is b) Presence of Foramen Transversarium.

2. A 25-year-old gymnast complains of lower back pain. An oblique X-ray reveals a "collar" on the "Scottie Dog" appearance. This fracture of the pars interarticularis affects which type of vertebra?

a) Cervical

b) Thoracic

c) Lumbar

d) Sacral

Explanation: Spondylolysis is a defect or stress fracture in the Pars Interarticularis (the isthmus of bone between the superior and inferior articular processes). This condition is classically seen in the Lumbar vertebrae, most commonly at L5. On an oblique radiograph, the posterior elements of a lumbar vertebra resemble a "Scottie Dog." A fracture of the pars appears as a radiolucent line across the neck of the dog (the "collar"). If the vertebra slips forward, it becomes Spondylolisthesis. This pathology is rare in thoracic or cervical regions. Therefore, the correct answer is c) Lumbar.

3. The "Hatchet-shaped" or quadrangular spinous process is a characteristic feature of which regional vertebrae?

a) Cervical

b) Thoracic

c) Lumbar

d) Coccygeal

Explanation: The shape of the spinous process correlates with the range of motion. Lumbar vertebrae have spinous processes that are short, thick, broad, and blunt, projecting directly backward (horizontally). This shape is often described as "Hatchet-shaped" or quadrangular. This robust structure provides a strong attachment for the massive back muscles (erector spinae) required for lifting and posture, and the horizontal gap between them facilitates lumbar puncture (spinal tap) when the spine is flexed. Thoracic spines are long and oblique; Cervical are bifid. Therefore, the correct answer is c) Lumbar.

4. An anesthetist plans to administer caudal epidural anesthesia for a difficult labor. The injection is delivered through the Sacral Hiatus. This opening is bounded bilaterally by the:

a) Sacral Promontory

b) Sacral Cornua

c) Ischial Spines

d) Posterior Superior Iliac Spines

Explanation: The Sacral Hiatus is an aperture located at the dorsal inferior aspect of the sacrum. It results from the incomplete fusion of the laminae of the fifth sacral vertebra (S5). The hiatus is flanked on either side by two bony projections known as the Sacral Cornua (horns), which represent the inferior articular processes of S5. These cornua are palpable landmarks used to locate the hiatus for the injection of local anesthetics into the epidural space (caudal block). The Sacral Promontory is the anterior superior margin of S1. Therefore, the correct answer is b) Sacral Cornua.

5. Which vertebra is unique because it lacks a vertebral body?

a) Axis (C2)

b) Atlas (C1)

c) Vertebra Prominens (C7)

d) T1

Explanation: The Atlas (C1) is the most atypical vertebra. During development, its centrum (body) fuses with the axis (C2) to become the Dens (Odontoid process). Consequently, the Atlas is left as a ring of bone consisting of an anterior arch, a posterior arch, and two lateral masses. It has no vertebral body and no spinous process (just a posterior tubercle). This ring-like structure supports the skull (occipital condyles) and allows for the "Yes" nodding movement at the atlanto-occipital joint. Therefore, the correct answer is b) Atlas (C1).

6. The costal facets (demifacets) located on the lateral sides of the vertebral body are the distinguishing characteristic of:

a) Cervical vertebrae

b) Thoracic vertebrae

c) Lumbar vertebrae

d) Sacral vertebrae

Explanation: The primary function of the thoracic cage is respiration and protection of viscera, involving the ribs. The Thoracic vertebrae are specialized to articulate with the ribs. To do this, they possess Costal Facets (or demifacets) on the sides of their vertebral bodies for the head of the rib, and costal facets on their transverse processes for the tubercle of the rib. No other vertebrae (cervical, lumbar, or sacral) have articular facets for ribs on their bodies. Thus, the presence of these facets is the defining feature of a thoracic vertebra. Therefore, the correct answer is b) Thoracic vertebrae.

7. A patient sustains a "Hangman's Fracture" following a high-speed motor vehicle accident where the neck was hyperextended. This specific injury involves a fracture of the:

a) Anterior arch of Atlas

b) Dens of Axis

c) Pars interarticularis (Pedicles) of Axis (C2)

d) Spinous process of C7

Explanation: A Hangman's Fracture is a traumatic spondylolisthesis of the Axis (C2). It typically results from forceful hyperextension of the neck (as seen in judicial hanging or chin-on-dashboard impacts). The fracture line passes bilaterally through the Pars Interarticularis (or pedicles) of the Axis (C2). This separates the posterior elements from the vertebral body, potentially allowing the body of C2 to slip anteriorly over C3. A fracture of the Atlas arches is a Jefferson fracture. A fracture of the Dens is an odontoid fracture. Therefore, the correct answer is c) Pars interarticularis (Pedicles) of Axis (C2).

8. The Mamillary processes are small tubercles found on the posterior edge of the superior articular processes. These are characteristic modifications seen in:

a) Cervical vertebrae

b) Thoracic vertebrae

c) Lumbar vertebrae

d) Sacral vertebrae

Explanation: In the transition from thoracic to lumbar, the muscular attachments change complexity. The Lumbar vertebrae possess distinct Mamillary processes located on the posterior aspect of the superior articular processes. These serve as attachment points for the multifidus muscle. Additionally, lumbar vertebrae have Accessory processes at the base of the transverse processes. While T12 may show a rudimentary mamillary process, they are the hallmark of the Lumbar spine. Cervical and typical Thoracic vertebrae lack these specific muscular processes. Therefore, the correct answer is c) Lumbar vertebrae.

9. To perform a Lumbar Puncture (LP), the needle is inserted into the subarachnoid space. The supracristal plane (Tuffier's line) connects the highest points of the iliac crests and crosses the spine at the level of the:

a) L1-L2 interspace

b) L2-L3 interspace

c) L3-L4 interspace or L4 spinous process

d) L5-S1 interspace

Explanation: Safe performance of a lumbar puncture requires inserting the needle below the termination of the spinal cord (Conus Medullaris). In adults, the cord ends at L1/L2. The standard anatomical landmark used to guide the needle is the Supracristal plane (Tuffier's line), drawn between the highest points of the iliac crests. This line reliably intersects the spine at the level of the L4 spinous process or the L3-L4 interspace (sometimes L4-L5). Inserting the needle at this level or one space below avoids injury to the cord, encountering only the nerve roots of the cauda equina. Therefore, the correct answer is c) L3-L4 interspace or L4 spinous process.

10. The Uncinate Processes (uncus) are lip-like elevations on the superior surface of the vertebral body. They form the unconovertebral joints (Joints of Luschka), which are potential sites of osteophyte formation in the:

a) Cervical spine

b) Thoracic spine

c) Lumbar spine

d) Sacral spine

Explanation: The Cervical vertebrae (specifically C3-C7) exhibit raised lateral margins on the superior surface of their bodies called Uncinate Processes. These articulate with the beveled inferior surface of the vertebra above to form the synovial Unconovertebral joints (Joints of Luschka). These "joints" add stability and limit lateral flexion. However, they are frequent sites of degeneration (spondylosis). Osteophytes (bone spurs) forming here can encroach on the intervertebral foramen, compressing the spinal nerve roots or the vertebral artery. These processes are not found in thoracic or lumbar vertebrae. Therefore, the correct answer is a) Cervical spine.

Chapter: Thorax Anatomy; Topic: Thoracic Cage; Subtopic: Components of the Chest Wall

Keyword Definitions:

• Chest Wall: Bony and muscular protective enclosure of thoracic organs, composed of ribs, sternum, thoracic vertebrae, and intercostal muscles.

• Thoracic Vertebrae: Twelve vertebrae forming posterior boundary of the thoracic cage.

• Sternum: Flat bone forming anterior midline support of thorax.

• Ribs: Curved bones forming major structural component of thoracic cage.

• Lumbar Vertebrae: Lower back vertebrae not included in chest wall formation.

1) Lead Question – 2016
All of the following is included in chest wall except?
A) Ribs
B) Thoracic Vertebrae
C) Sternum
D) Lumbar vertebrae

Answer: D) Lumbar vertebrae

Explanation: The chest wall consists of the ribs, costal cartilages, sternum, and thoracic vertebrae. These structures collectively protect thoracic organs such as the heart and lungs and provide attachment for respiratory muscles. Lumbar vertebrae are located below the thoracic region and are not part of the thoracic cage. They do not contribute to chest wall formation or respiratory mechanics. Therefore, the only option that is not included in the chest wall is the lumbar vertebrae, making option D correct.

2) True ribs are defined as those that–
A) Attach directly to sternum
B) Do not attach to sternum
C) Attach to vertebrae only
D) Are floating

Answer: A) Attach directly to sternum

Explanation: True ribs (1–7) connect directly to sternum via costal cartilage. Thus, A is correct.

3) Floating ribs are–
A) 1–2
B) 3–5
C) 11–12
D) 7–8

Answer: C) 11–12

Explanation: Ribs 11–12 do not attach anteriorly. Thus, C is correct.

4) Manubriosternal joint is a–
A) Synovial joint
B) Secondary cartilaginous joint
C) Primary cartilaginous joint
D) Fibrous joint

Answer: B) Secondary cartilaginous joint

Explanation: Manubrium + body of sternum join by symphysis. Thus, B is correct.

5) Which rib articulates with the sternal angle?
A) 1st
B) 2nd
C) 3rd
D) 5th

Answer: B) 2nd

Explanation: The second rib attaches at manubriosternal junction. Thus, B is correct.

6) The intercostal neurovascular bundle lies between–
A) Internal & innermost intercostals
B) External & internal intercostals
C) Rib & external intercostals
D) Sternum & costal cartilage

Answer: A) Internal & innermost intercostals

Explanation: VAN lies in intercostal groove protected by these muscles. Thus, A is correct.

7) A stab wound at midaxillary line affecting the 5th intercostal space may injure–
A) Lung
B) Diaphragm
C) Liver
D) Spleen

Answer: A) Lung

Explanation: Midaxillary 5th ICS corresponds to lung field. Thus, A is correct.

8) Rib notching on X-ray indicates enlargement of–
A) Intercostal arteries
B) Internal mammary artery
C) Aorta
D) Pulmonary artery

Answer: A) Intercostal arteries

Explanation: Seen in coarctation of aorta from dilated intercostals. Thus, A is correct.

9) Typical rib contains all except–
A) Head
B) Neck
C) Tubercle
D) Manubrium

Answer: D) Manubrium

Explanation: Manubrium is part of sternum, not rib. Thus, D is correct.

10) Upper thoracic vertebrae are unique due to–
A) Costal facets
B) Transverse foramina
C) Bifid spinous processes
D) Large vertebral body

Answer: A) Costal facets

Explanation: Thoracic vertebrae articulate with ribs via costal facets. Thus, A is correct.

11) Intercostal spaces are widest at–
A) Upper thorax
B) Lower thorax
C) Mid-thorax
D) Apex

Answer: C) Mid-thorax

Explanation: Widest around 6–7th ribs allowing better expansion. Thus, C is correct.

Chapter: Knee Anatomy; Topic: Posterior Knee Structures; Subtopic: Oblique Popliteal Ligament

Keyword Definitions:

• Oblique Popliteal Ligament: Strong posterior ligament of knee derived from semimembranosus tendon.

• Semimembranosus: Hamstring muscle whose expansions stabilize posterior knee.

• Popliteal Fossa: Diamond-shaped space behind knee containing major vessels and nerves.

• Posterior Capsule: Fibrous layer reinforcing knee joint from the back.

• Biceps Femoris: Lateral hamstring inserting on fibular head, not forming this ligament.

1) Lead Question – 2016
Oblique popliteal ligament is derived from?
A) Semitendinosus
B) Biceps femoris
C) Adductor magnus
D) Semimembranosus

Answer: D) Semimembranosus

Explanation: The oblique popliteal ligament is a key reinforcement of the posterior knee capsule and is derived from the reflected fibers of the semimembranosus tendon. It reinforces the posterior capsule, supports the knee during extension, and forms part of the floor of the popliteal fossa. Semitendinosus does not form this structure, while biceps femoris inserts laterally onto the fibular head. Adductor magnus inserts at the adductor tubercle and does not contribute to posterior capsule formation. Therefore, semimembranosus is the correct origin of the oblique popliteal ligament.

2) The posterior oblique ligament helps resist–
A) Valgus stress
B) Varus stress
C) Posterior tibial translation
D) Anterior tibial translation

Answer: C) Posterior tibial translation

Explanation: The posterior oblique ligament prevents posterior tibial movement, complementing PCL. Thus, C is correct.

3) Semimembranosus inserts mainly on–
A) Lateral tibial condyle
B) Medial tibial condyle
C) Fibular head
D) Patella

Answer: B) Medial tibial condyle

Explanation: Semimembranosus inserts posteriorly on medial condyle of tibia. Thus, B is correct.

4) A tear of the posterior capsule would most likely affect which structure?
A) Oblique popliteal ligament
B) LCL
C) ACL
D) Medial meniscus

Answer: A) Oblique popliteal ligament

Explanation: Oblique popliteal ligament reinforces the posterior capsule. Thus, A is correct.

5) The popliteal fossa contains all except–
A) Popliteal artery
B) Tibial nerve
C) Peroneal artery
D) Popliteal vein

Answer: C) Peroneal artery

Explanation: Peroneal artery lies deep in leg, not popliteal fossa. Thus, C is correct.

6) Which muscle forms the superomedial border of popliteal fossa?
A) Semimembranosus
B) Sartorius
C) Rectus femoris
D) Biceps femoris

Answer: A) Semimembranosus

Explanation: Semimembranosus forms upper medial boundary. Thus, A is correct.

7) The oblique popliteal ligament attaches to–
A) Lateral femoral condyle
B) Medial epicondyle
C) Fibular head
D) Iliac crest

Answer: A) Lateral femoral condyle

Explanation: It runs from semimembranosus to lateral femoral condyle. Thus, A is correct.

8) Posterior knee pain during extension suggests injury to–
A) Popliteus
B) Oblique popliteal ligament
C) ACL
D) Quadriceps

Answer: B) Oblique popliteal ligament

Explanation: Posterior capsule stretch stresses oblique popliteal ligament. Thus, B is correct.

9) The ligament reinforcing posterolateral knee is–
A) Arcuate ligament
B) MCL
C) ACL
D) PCL

Answer: A) Arcuate ligament

Explanation: Arcuate ligament stabilizes posterolateral complex. Thus, A is correct.

10) Semitendinosus forms part of–
A) Pes anserinus
B) IT band
C) Quadriceps tendon
D) Patellar retinaculum

Answer: A) Pes anserinus

Explanation: Semitendinosus with sartorius and gracilis forms pes anserinus. Thus, A is correct.

11) Popliteus muscle unlocks knee by rotating–
A) Tibia internally
B) Tibia externally
C) Femur laterally
D) Patella medially

Answer: C) Femur laterally

Explanation: Popliteus externally rotates femur on tibia to unlock knee. Thus, C is correct.

Chapter: Back & Pelvic Anatomy; Topic: Sacral Attachments; Subtopic: Muscular Attachments on Posterior Sacrum

Keyword Definitions:

• Sacrum: Triangular bone formed by fusion of five sacral vertebrae, providing attachment to back and pelvic muscles.

• Multifidus Lumborum: Deep back muscle attaching to sacrum and stabilizing vertebral column.

• Piriformis: Muscle originating from anterior sacrum, exiting via greater sciatic foramen.

• Iliacus: Muscle arising from iliac fossa, not the sacrum.

• Coccygeus: Pelvic floor muscle attached to coccyx and ischial spine, not posterior sacrum.

1) Lead Question – 2016
Attachment on posterior surface of sacrum?
A) Multifidus lumborum
B) Iliacus
C) Coccygeus
D) Piriformis

Answer: A) Multifidus lumborum

Explanation: Multifidus lumborum is a deep intrinsic back muscle that arises from the posterior sacrum, dorsal sacroiliac ligaments, and posterior superior iliac spine. It stabilizes lumbar vertebrae and is part of the transversospinalis group. Iliacus takes origin from the iliac fossa, not the sacrum. Coccygeus attaches to the coccyx and ischial spine. Piriformis originates from the anterior, not posterior, sacral surface. Thus, the only structure clearly attached to the posterior surface of the sacrum is multifidus lumborum.

2) Piriformis arises from–
A) Posterior sacrum
B) Anterior sacrum
C) Coccyx
D) Iliac crest

Answer: B) Anterior sacrum

Explanation: Piriformis originates from anterior sacral foramina. Thus, B is correct.

3) Coccygeus inserts on–
A) Coccyx
B) L5 vertebra
C) Ilium
D) Pubis

Answer: A) Coccyx

Explanation: Coccygeus attaches to ischial spine and coccyx. Thus, A is correct.

4) Multifidus is part of–
A) Erector spinae
B) Transversospinalis group
C) Pelvic diaphragm
D) Abdominal wall

Answer: B) Transversospinalis group

Explanation: Multifidus belongs to deep intrinsic back muscles. Thus, B is correct.

5) A patient with sacral back pain may have strain of–
A) Multifidus
B) Rectus femoris
C) Vastus medialis
D) Soleus

Answer: A) Multifidus

Explanation: Multifidus attaches on posterior sacrum; strain causes localized pain. Thus, A is correct.

6) Iliacus joins which muscle to form iliopsoas?
A) Psoas major
B) Rectus femoris
C) Sartorius
D) Pectineus

Answer: A) Psoas major

Explanation: Iliacus + psoas major form iliopsoas. Thus, A is correct.

7) Piriformis exits pelvis through–
A) Lesser sciatic foramen
B) Greater sciatic foramen
C) Obturator canal
D) Inguinal canal

Answer: B) Greater sciatic foramen

Explanation: Piriformis divides the greater sciatic foramen. Thus, B is correct.

8) Multifidus function includes–
A) Hip extension
B) Vertebral stabilization
C) Shoulder abduction
D) Knee flexion

Answer: B) Vertebral stabilization

Explanation: Multifidus stabilizes spine during posture. Thus, B is correct.

9) Coccygeus helps form–
A) Pelvic diaphragm
B) Thoracic diaphragm
C) Urogenital diaphragm
D) Lumbar plexus

Answer: A) Pelvic diaphragm

Explanation: Coccygeus with levator ani forms pelvic diaphragm. Thus, A is correct.

10) A tight piriformis may compress–
A) Femoral nerve
B) Sciatic nerve
C) Pudendal nerve
D) Genitofemoral nerve

Answer: B) Sciatic nerve

Explanation: Piriformis syndrome results from sciatic nerve compression. Thus, B is correct.

11) Posterior sacral foramina transmit–
A) Dorsal rami
B) Ventral rami
C) Sacral plexus
D) Femoral nerve

Answer: A) Dorsal rami

Explanation: Posterior foramina transmit dorsal rami supplying back muscles including multifidus. Thus, A is correct.

Chapter: Lower Limb Anatomy; Topic: Ankle & Foot Tendons; Subtopic: Tendons around the Lateral Malleolus

Keyword Definitions:

• Peroneus (Fibularis) Longus: Lateral compartment muscle whose tendon passes posterior to lateral malleolus.

• Lateral Malleolus Groove: Fibular groove on posterior surface of fibula guiding peroneal tendons.

• Peroneal Retinacula: Bands stabilizing peroneal tendons behind lateral malleolus.

• Tibialis Posterior: Medial compartment muscle passing posterior to medial malleolus.

• Flexor Hallucis Longus (FHL): Posterior compartment muscle passing behind medial malleolus through separate tunnel.

1) Lead Question – 2016
Which tendon is lodged in the groove on posterior surface of lateral malleolus?
A) Peroneus longus
B) Tibialis anterior
C) Tibialis posterior
D) Flexor hallucis longus

Answer: A) Peroneus longus

Explanation: The posterior surface of the lateral malleolus features a distinct groove that accommodates the tendons of both peroneus longus and peroneus brevis. These tendons are stabilized by the superior and inferior peroneal retinacula and are essential for ankle eversion and lateral stability. Tibialis anterior runs anterior to the ankle, tibialis posterior runs behind the medial malleolus, and FHL also passes medially. Thus, the tendon lodged in the groove on the posterior aspect of the lateral malleolus is peroneus longus.

2) The tendon lying most anterior behind lateral malleolus is–
A) Peroneus longus
B) Peroneus brevis
C) FHL
D) Tibialis anterior

Answer: B) Peroneus brevis

Explanation: Peroneus brevis lies anterior to peroneus longus in the common peroneal sheath. Thus, B is correct.

3) The action of peroneus longus is–
A) Foot inversion
B) Foot eversion and plantarflexion
C) Dorsiflexion
D) Toe extension

Answer: B) Foot eversion and plantarflexion

Explanation: Peroneus longus stabilizes arch and everts foot. Thus, B is correct.

4) Peroneal tendons are stabilised by–
A) Flexor retinaculum
B) Superior peroneal retinaculum
C) Extensor retinaculum
D) Spring ligament

Answer: B) Superior peroneal retinaculum

Explanation: SPR holds both peroneal tendons behind lateral malleolus. Thus, B is correct.

5) Tibialis posterior passes behind which malleolus?
A) Lateral
B) Medial
C) Both
D) None

Answer: B) Medial

Explanation: Tibialis posterior forms part of Tom-Dick-And-Harry group behind medial malleolus. Thus, B is correct.

6) A patient with pain behind lateral malleolus likely has–
A) Peroneal tendinopathy
B) Tibialis posterior tear
C) FHL tenosynovitis
D) Achilles rupture

Answer: A) Peroneal tendinopathy

Explanation: Posterolateral ankle pain is classic for peroneal tendon injury. Thus, A is correct.

7) The muscle helping maintain transverse arch is–
A) FHL
B) Peroneus longus
C) Tibialis anterior
D) Gastrocnemius

Answer: B) Peroneus longus

Explanation: PL forms a sling with tibialis anterior across sole. Thus, B is correct.

8) Peroneus brevis inserts on–
A) Base of 1st metatarsal
B) Medial cuneiform
C) Tuberosity of 5th metatarsal
D) Navicular

Answer: C) Tuberosity of 5th metatarsal

Explanation: PB inserts on the styloid of 5th metatarsal. Thus, C is correct.

9) FHL tendon passes through–
A) Sustentaculum tali groove
B) Fibular groove
C) Tarsal tunnel
D) Cuboid fossa

Answer: A) Sustentaculum tali groove

Explanation: FHL tendon uses sustentaculum tali pulley. Thus, A is correct.

10) In eversion sprain, commonly injured structure is–
A) Lateral ligament complex
B) Deltoid ligament
C) Spring ligament
D) Peroneal retinaculum

Answer: B) Deltoid ligament

Explanation: Eversion injury stresses strong medial deltoid ligament. Thus, B is correct.

11) A patient with foot drop will have weakness of–
A) Peroneus longus
B) Tibialis anterior
C) Tibialis posterior
D) Gastrocnemius

Answer: B) Tibialis anterior

Explanation: TA is main dorsiflexor supplied by deep peroneal nerve. Thus, B is correct.

Chapter: Lower Limb Anatomy; Topic: Tibia – Surface Anatomy & Attachments;
Subtopic: Lateral Tibial Condyle

Keyword Definitions:

• Lateral Tibial Condyle: Upper lateral expanded part of tibia receiving attachments such as iliotibial tract.

• Iliotibial Tract (ITT): Thickened fascia lata band inserting on Gerdy’s tubercle of lateral tibia.

• Gerdy's Tubercle: Prominent area on lateral condyle where ITT inserts.

• Ligamentum Patellae: Continuation of quadriceps tendon inserting on tibial tuberosity.

• Collateral Ligaments: Medial and lateral stabilizing ligaments attached to tibia and femur.

1) Lead Question – 2016
What is true about lateral tibial condyle?
A) Iliotibial tract is attached to the lateral condyle of tibia
B) Ligamentum patellae inserts on it
C) Medial collateral ligament is attached to it
D) Semimembranosus is attached to it

Answer: A) Iliotibial tract is attached to the lateral condyle of tibia

Explanation: The lateral tibial condyle bears a prominent area called Gerdy’s tubercle where the iliotibial tract inserts. This attachment helps stabilize the lateral knee during movement. Ligamentum patellae does not attach here; instead, it inserts on the tibial tuberosity located anteriorly. Medial collateral ligament attaches to the medial condyle, not the lateral one. Semimembranosus inserts on the posteromedial aspect of tibia, not on the lateral condyle. Hence, the only correct statement regarding the lateral tibial condyle is that it receives the iliotibial tract.

2) The tibial tuberosity is the insertion of–
A) Semitendinosus
B) Ligamentum patellae
C) Sartorius
D) IT band

Answer: B) Ligamentum patellae

Explanation: Ligamentum patellae continues from the patella to insert on tibial tuberosity. Thus, B is correct.

3) Gerdy’s tubercle receives attachment of–
A) Tensor fascia lata
B) Sartorius
C) Gracilis
D) Semimembranosus

Answer: A) Tensor fascia lata

Explanation: TFL inserts via iliotibial tract onto Gerdy’s tubercle. Thus, A is correct.

4) Medial condyle of tibia gives insertion to–
A) Semimembranosus
B) Biceps femoris
C) IT band
D) Popliteus

Answer: A) Semimembranosus

Explanation: Semimembranosus inserts on posteromedial tibia. Thus, A is correct.

5) Popliteus inserts on–
A) Posterior tibia above soleal line
B) Lateral tibial condyle
C) Medial tibial condyle
D) Intercondylar eminence

Answer: A) Posterior tibia above soleal line

Explanation: Popliteus unlocks knee and inserts above the soleal line. Thus, A is correct.

6) A patient with lateral knee pain likely has inflammation of–
A) IT band at Gerdy's tubercle
B) Pes anserinus
C) Sartorius insertion
D) Popliteus tendon

Answer: A) IT band at Gerdy's tubercle

Explanation: Lateral knee pain is classic for IT band syndrome. Thus, A is correct.

7) The lateral condyle of tibia articulates with–
A) Medial femoral condyle
B) Lateral femoral condyle
C) Patella
D) Fibular head

Answer: B) Lateral femoral condyle

Explanation: Knee joint articulation pairs same-sided condyles. Thus, B is correct.

8) Fibular collateral ligament attaches to–
A) Tibia
B) Fibular head
C) Medial tibial condyle
D) Patella

Answer: B) Fibular head

Explanation: LCL spans from lateral femoral epicondyle to fibular head. Thus, B is correct.

9) Pes anserinus is formed by–
A) Sartorius, gracilis, semitendinosus
B) ITB, TFL, biceps femoris
C) Gastrocnemius heads
D) Popliteus, soleus, plantaris

Answer: A) Sartorius, gracilis, semitendinosus

Explanation: These three muscles form the goose-foot insertion. Thus, A is correct.

10) The intercondylar eminence is important for attachment of–
A) CL ligaments
B) Cruciate ligaments
C) Hamstrings
D) IT band

Answer: B) Cruciate ligaments

Explanation: ACL and PCL attach here. Thus, B is correct.

11) Injury to lateral condyle may affect–
A) IT band stability
B) Semimembranosus
C) Pes anserinus
D) MCL

Answer: A) IT band stability

Explanation: ITB insertion lies on lateral tibial condyle; trauma affects stability. Thus, A is correct.

Chapter: Upper Limb Anatomy; Topic: Scapula – Palpable Landmarks; Subtopic: Coracoid Process & Surface Anatomy

Keyword Definitions:

• Coracoid Process: An anterior projection of scapula palpable in infraclavicular fossa.

• Spine of Scapula: A posterior ridge dividing supraspinous and infraspinous fossae.

• Infraclavicular Fossa: Depression below clavicle bounded by deltoid and pectoralis major.

• Scapular Landmarks: Anatomical points used for clinical palpation and muscle attachment.

• Anterior Scapular Palpation: Palpation of coracoid process through deltopectoral groove.

1) Lead Question – 2016
Which part of scapula can be palpated in the infraclavicular fossa?
A) Coracoid process
B) Spine of scapula
C) Inferior angle
D) Supraspinous fossa

Answer: A) Coracoid process

Explanation: The coracoid process is a hook-like projection of the scapula that lies anteriorly and can be easily felt in the infraclavicular fossa, specifically within the deltopectoral groove. It serves as an attachment for pectoralis minor, short head of biceps, and coracobrachialis. The spine of scapula and supraspinous fossa are posterior structures and cannot be palpated anteriorly. The inferior angle is located posteroinferiorly. Hence, the only structure palpable in the infraclavicular region is the coracoid process, making option A correct.

2) The coracoid process gives attachment to–
A) Supraspinatus
B) Pectoralis minor
C) Teres major
D) Infraspinatus

Answer: B) Pectoralis minor

Explanation: Pectoralis minor originates from ribs 3–5 and inserts on coracoid process. Thus, B is correct.

3) The structure passing through the deltopectoral groove is–
A) Cephalic vein
B) Basilic vein
C) Subclavian artery
D) Thoracoacromial nerve

Answer: A) Cephalic vein

Explanation: Cephalic vein runs in deltopectoral groove close to coracoid. Thus, A is correct.

4) A surgeon palpates coracoid process to locate origin of–
A) Long head of biceps
B) Short head of biceps
C) Triceps lateral head
D) Trapezius

Answer: B) Short head of biceps

Explanation: Short head arises from coracoid process. Thus, B is correct.

5) Which artery lies close to coracoid process during procedures?
A) Thoracoacromial artery
B) Axillary artery
C) Radial artery
D) Ulnar artery

Answer: B) Axillary artery

Explanation: Axillary artery passes inferior to coracoid, clinically important. Thus, B is correct.

6) The inferior angle of scapula is located at vertebral level–
A) T1
B) T7
C) T12
D) L1

Answer: B) T7

Explanation: Inferior angle aligns with T7 spinous process. Thus, B is correct.

7) Supraspinous fossa contains–
A) Subscapularis
B) Supraspinatus
C) Infraspinatus
D) Teres minor

Answer: B) Supraspinatus

Explanation: Supraspinatus lies above the spine in supraspinous fossa. Thus, B is correct.

8) Axillary nerve can be palpated near–
A) Coracoid process
B) Surgical neck of humerus
C) Manubrium
D) Medial epicondyle

Answer: B) Surgical neck of humerus

Explanation: It winds around surgical neck with posterior circumflex humeral artery. Thus, B is correct.

9) A patient with shoulder trauma has tenderness at coracoid. Likely injured muscle is–
A) Pectoralis minor
B) Teres major
C) Deltoid
D) Supraspinatus

Answer: A) Pectoralis minor

Explanation: Pectoralis minor inserts on coracoid and is involved in anterior shoulder trauma. Thus, A is correct.

10) The coracoclavicular ligament attaches coracoid to–
A) Manubrium
B) Clavicle
C) Scapular spine
D) Humerus

Answer: B) Clavicle

Explanation: It stabilizes AC joint via conoid and trapezoid parts. Thus, B is correct.

11) The coracoacromial arch prevents–
A) Inferior migration of humeral head
B) Superior migration of humeral head
C) Rotation of scapula
D) Medial humeral shift

Answer: B) Superior migration of humeral head

Explanation: Arch formed by coracoid + acromion + ligament acts as superior restraint. Thus, B is correct.

Chapter: Upper Limb Anatomy; Topic: Shoulder Joint Ligaments; Subtopic: Coracohumeral Ligament Attachments

Keyword Definitions:

• Coracohumeral Ligament: Strong ligament extending from the coracoid process to the humerus, providing superior stability.

• Greater Tuberosity: Lateral prominence of humerus where supraspinatus, infraspinatus, and teres minor insert.

• Lesser Tuberosity: Medial prominence where subscapularis inserts.

• Bicipital Groove: Groove between tuberosities holding long head of biceps tendon.

• Shoulder Stabilizing Ligaments: Ligaments supporting humeral head stability including coracohumeral ligament.

1) Lead Question – 2016
Coracohumeral ligament inserts on?
A) Greater tuberosity
B) Lesser and greater tuberosities
C) Anatomical neck of humerus
D) Bicipital groove

Answer: B) Lesser and greater tuberosities

Explanation: The coracohumeral ligament originates from the lateral border of the coracoid process and splits into two bands. One band inserts onto the lesser tuberosity and blends with the subscapularis tendon, while the other band inserts onto the greater tuberosity alongside the supraspinatus tendon. This arrangement provides superior reinforcement to the shoulder joint capsule and checks inferior translation of the humeral head. Because the ligament attaches to both tuberosities, the correct answer is B. It does not attach to the anatomical neck or the bicipital groove.

2) The coracohumeral ligament primarily prevents–
A) Posterior dislocation
B) Inferior displacement of humeral head
C) Upward migration of humerus
D) External rotation

Answer: B) Inferior displacement of humeral head

Explanation: It acts as a superior stabilizer resisting inferior pull. Thus, B is correct.

3) Which ligament forms the coracoacromial arch?
A) Coracohumeral
B) Coracoacromial
C) Glenohumeral
D) Costoclavicular

Answer: B) Coracoacromial

Explanation: Coracoacromial ligament forms the protective arch. Thus, B is correct.

4) A patient with inferior shoulder instability likely has damage to–
A) SGHL
B) Coracohumeral ligament
C) Transverse humeral ligament
D) AC ligament

Answer: B) Coracohumeral ligament

Explanation: Coracohumeral ligament stabilizes against inferior translation. Thus, B is correct.

5) The transverse humeral ligament stabilizes–
A) Long head of biceps tendon
B) Subscapularis tendon
C) AC joint capsule
D) Labrum

Answer: A) Long head of biceps tendon

Explanation: It converts the bicipital groove into a canal. Thus, A is correct.

6) Glenohumeral ligaments are best seen in which position?
A) Neutral
B) External rotation
C) Internal rotation
D) Flexion

Answer: B) External rotation

Explanation: External rotation tensions GH ligaments making them visible. Thus, B is correct.

7) Injury to suprascapular nerve affects which movement most?
A) Internal rotation
B) Initial abduction
C) Extension
D) Adduction

Answer: B) Initial abduction

Explanation: Supraspinatus initiates abduction. Thus, B is correct.

8) Which muscle inserts on the greater tuberosity?
A) Subscapularis
B) Supraspinatus
C) Teres major
D) Latissimus dorsi

Answer: B) Supraspinatus

Explanation: Supraspinatus, infraspinatus, and teres minor insert there. Thus, B is correct.

9) Coracoid process gives attachment to all except–
A) Short head of biceps
B) Coracobrachialis
C) Pectoralis minor
D) Deltoid

Answer: D) Deltoid

Explanation: Deltoid attaches to clavicle, acromion, and scapular spine. Thus, D is correct.

10) A patient with upward migration of humeral head likely has–
A) Massive rotator cuff tear
B) Axillary nerve injury
C) Clavicle fracture
D) Glenoid labrum tear

Answer: A) Massive rotator cuff tear

Explanation: Loss of cuff support permits superior displacement. Thus, A is correct.

11) The lesser tuberosity receives insertion of–
A) Infraspinatus
B) Supraspinatus
C) Subscapularis
D) Teres minor

Answer: C) Subscapularis

Explanation: Subscapularis inserts solely on the lesser tuberosity. Thus, C is correct.

Chapter: Upper Limb Anatomy; Topic: Shoulder Joint Ligaments; Subtopic: Coracoacromial Arch & Stability

Keyword Definitions:

• Coracoacromial Ligament: A strong triangular ligament spanning between coracoid process and acromion, forming the coracoacromial arch.

• Coracoacromial Arch: Superior protective roof over the shoulder joint preventing upward displacement of humeral head.

• Humeral Head Displacement: Abnormal superior or inferior movement of humeral head due to ligament or muscle dysfunction.

• Shoulder Stability Structures: Rotator cuff muscles, capsule, labrum, and ligaments that prevent dislocation.

• Upward Migration of Humerus: Superior movement resisted mainly by coracoacromial arch.

1) Lead Question – 2016
Coracoacromial ligament resists which movements?
A) Upward displacement of humeral head
B) Abduction of shoulder
C) Inferior displacement of humerus
D) External rotation

Answer: A) Upward displacement of humeral head

Explanation: The coracoacromial ligament forms the superior boundary of the shoulder joint along with the coracoacromial arch. Its primary function is to resist upward displacement of the humeral head, especially when strong forces are transmitted through the rotator cuff. The ligament prevents superior migration of the humerus and thus acts as a protective stabilizing structure. It has no direct role in resisting abduction, inferior displacement, or external rotation. Therefore, the correct answer is A. This ligament becomes important in conditions like rotator cuff tears where superior humeral migration may occur.

2) Which ligament forms the coracoacromial arch?
A) Coracoclavicular ligament
B) Coracoacromial ligament
C) Glenohumeral ligament
D) Transverse humeral ligament

Answer: B) Coracoacromial ligament

Explanation: The coracoacromial arch is created by the coracoacromial ligament spanning between coracoid and acromion. Thus, B is correct.

3) The structure preventing inferior dislocation of humeral head is–
A) Deltoid
B) Superior glenohumeral ligament
C) Coracoacromial ligament
D) Long head of triceps

Answer: B) Superior glenohumeral ligament

Explanation: SGHL stabilizes against inferior translation in adducted arm. Thus, B is correct.

4) A patient with massive rotator cuff tear may show–
A) Upward migration of humeral head
B) Inferior laxity
C) Frozen shoulder
D) No change in humeral head position

Answer: A) Upward migration of humeral head

Explanation: Loss of cuff tension permits upward displacement resisted only by coracoacromial arch. Thus, A is correct.

5) The coracoclavicular ligament stabilizes–
A) AC joint
B) Glenohumeral joint
C) Sternoclavicular joint
D) Scapulothoracic articulation

Answer: A) AC joint

Explanation: CC ligament (conoid & trapezoid) anchors clavicle to coracoid, stabilizing AC joint. Thus, A is correct.

6) Which muscle helps resist upward humeral displacement?
A) Latissimus dorsi
B) Supraspinatus
C) Pectoralis minor
D) Trapezius

Answer: B) Supraspinatus

Explanation: Supraspinatus compresses humeral head and prevents superior migration. Thus, B is correct.

7) Injury to which nerve may weaken shoulder abduction initiation?
A) Axillary nerve
B) Suprascapular nerve
C) Radial nerve
D) Ulnar nerve

Answer: B) Suprascapular nerve

Explanation: Suprascapular nerve supplies supraspinatus which initiates abduction. Thus, B is correct.

8) The transverse humeral ligament stabilizes–
A) Biceps long head tendon
B) Subscapularis tendon
C) AC joint capsule
D) Axillary artery

Answer: A) Biceps long head tendon

Explanation: It holds biceps tendon in the bicipital groove. Thus, A is correct.

9) A painful arc between 60–120 degrees of abduction usually indicates–
A) AC joint arthritis
B) Subacromial impingement
C) GH dislocation
D) Rotator cuff rupture

Answer: B) Subacromial impingement

Explanation: Compression of supraspinatus tendon under coracoacromial arch causes this painful arc. Thus, B is correct.

10) The ligament preventing anterior humeral head displacement is–
A) Coracoacromial
B) Middle glenohumeral ligament
C) Coracoclavicular
D) Interclavicular

Answer: B) Middle glenohumeral ligament

Explanation: MGHL resists anterior translation especially in mid-range motion. Thus, B is correct.

11) Coracoid process provides attachment for all except–
A) Coracoacromial ligament
B) Coracoclavicular ligament
C) Short head of biceps
D) Deltoid

Answer: D) Deltoid

Explanation: Deltoid originates from clavicle, acromion, and spine of scapula, not coracoid. Thus, D is correct.

Chapter: Upper Limb Anatomy; Topic: Shoulder Joint & Movements; Subtopic: Muscles of Abduction

Keyword Definitions:

• Shoulder Abduction: Movement of arm away from body’s midline in coronal plane.

• Supraspinatus: Initiates first 0–15° of abduction.

• Deltoid Muscle: Principal abductor from 15–90°.

• Trapezius: Helps upward rotation of scapula beyond 90°.

• Serratus Anterior: Stabilizes scapula and aids overhead abduction.

1) Lead Question – 2016
Which of the following muscles carries out shoulder abduction from 15 to 90 degrees?
A) Supraspinatus
B) Trapezius
C) Deltoid
D) Serratus Anterior

Answer: C) Deltoid

Explanation: Shoulder abduction is initiated by supraspinatus for the first 15 degrees. From 15 to 90 degrees, the deltoid muscle—particularly its middle fibers—acts as the prime mover. Beyond 90 degrees, scapular rotation performed by trapezius and serratus anterior becomes essential. Therefore, among the provided options, deltoid is the correct muscle responsible for abduction from 15° to 90°. This division of abduction responsibility helps in clinical examination of rotator cuff integrity and nerve injuries such as axillary nerve palsy.

2) Supraspinatus initiates shoulder abduction up to–
A) 5°
B) 10°
C) 15°
D) 45°

Answer: C) 15°

Explanation: Supraspinatus is responsible for the first 15° of abduction before deltoid takes over. Thus, C is correct.

3) The deltoid muscle is supplied by–
A) Suprascapular nerve
B) Axillary nerve
C) Radial nerve
D) Median nerve

Answer: B) Axillary nerve

Explanation: The axillary nerve (C5–C6) innervates the deltoid and teres minor. Injury affects abduction. Thus, B is correct.

4) A patient with winged scapula has paralysis of–
A) Trapezius
B) Supraspinatus
C) Serratus anterior
D) Deltoid

Answer: C) Serratus anterior

Explanation: Winged scapula results from long thoracic nerve injury affecting serratus anterior. Thus, C is correct.

5) Upward rotation of the scapula during overhead abduction is mainly by–
A) Deltoid
B) Trapezius
C) Teres minor
D) Latissimus dorsi

Answer: B) Trapezius

Explanation: Trapezius rotates the scapula after 90° of abduction. Thus, B is correct.

6) Which muscle forms the rounded contour of the shoulder?
A) Deltoid
B) Supraspinatus
C) Subscapularis
D) Trapezius

Answer: A) Deltoid

Explanation: Deltoid gives shoulder its rounded shape. Thus, A is correct.

7) Axillary nerve injury leads to loss of sensation over–
A) Medial arm
B) Lateral shoulder
C) Forearm
D) Thumb

Answer: B) Lateral shoulder

Explanation: Axillary nerve supplies the superior lateral cutaneous nerve area. Thus, B is correct.

8) Teres minor assists in–
A) Abduction
B) Medial rotation
C) Lateral rotation
D) Flexion

Answer: C) Lateral rotation

Explanation: Teres minor, supplied by axillary nerve, laterally rotates the arm. Thus, C is correct.

9) Rotator cuff does NOT include–
A) Supraspinatus
B) Infraspinatus
C) Teres major
D) Subscapularis

Answer: C) Teres major

Explanation: Teres major is not part of rotator cuff whereas the other three are. Thus, C is correct.

10) Injury to suprascapular nerve affects which movements?
A) Abduction initiation & lateral rotation
B) Medial rotation only
C) Elbow flexion
D) Forearm pronation

Answer: A) Abduction initiation & lateral rotation

Explanation: Supraspinatus (abduction) and infraspinatus (lateral rotation) are supplied by suprascapular nerve. Thus, A is correct.

11) Deltoid paralysis leads to difficulty in raising the arm beyond–
A) 10°
B) 15°
C) 30°
D) 90°

Answer: B) 15°

Explanation: After the first 15°, deltoid is essential. Paralysis prevents further abduction. Thus, B is correct.

Chapter: Upper Limb Anatomy; Topic: Scapula; Subtopic: Surface Markings and Vertebral Levels

Keyword Definitions:

• Scapular Spine: Prominent ridge on posterior scapula, dividing supraspinous and infraspinous fossae.

• Vertebral Level Landmarks: Surface markers used clinically to identify internal structures with external palpation.

• Inferior Angle of Scapula: Lowest point of scapula, lies near T7 vertebral level.

• Acromion: Lateral continuation of scapular spine forming part of shoulder.

• Scapular Borders: Medial, lateral, and superior edges forming anatomical reference points.

1) Lead Question – 2016
What is the level of the spine of scapula?
A) T7
B) T10
C) T4
D) T2

Answer: C) T4

Explanation: The spine of the scapula corresponds most closely to the level of the T3 vertebra. However, clinical surface anatomy often places it between T3–T4, and in exam-based options, T4 is the accepted closest match. T7 corresponds to the inferior angle of the scapula, not the spine. T10 is far lower and unrelated to scapular landmarks. T2 lies superior to the scapular spine. Therefore, among the given choices, T4 is the correct answer. Knowledge of vertebral level correlations is crucial in clinical examination, anesthesia techniques, and radiological interpretation.

2) The inferior angle of the scapula corresponds to which vertebral level?
A) T2
B) T7
C) L1
D) T4

Answer: B) T7

Explanation: The inferior angle is classically at T7. Thus, B is correct.

3) The root of the spine of scapula corresponds most closely to–
A) T3
B) T6
C) T8
D) T1

Answer: A) T3

Explanation: Anatomically, the spine's medial end aligns with T3. Thus, A is correct.

4) A patient with shoulder trauma loses function of supraspinatus. The muscle originates from–
A) Infraspinous fossa
B) Supraspinous fossa
C) Subscapular fossa
D) Acromion

Answer: B) Supraspinous fossa

Explanation: Supraspinatus arises from supraspinous fossa, above the spine of scapula. Thus, B is correct.

5) Which nerve innervates the infraspinatus muscle?
A) Axillary nerve
B) Suprascapular nerve
C) Spinal accessory nerve
D) Dorsal scapular nerve

Answer: B) Suprascapular nerve

Explanation: Suprascapular nerve supplies both supraspinatus and infraspinatus. Thus, B is correct.

6) The acromion articulates with which bone?
A) Sternum
B) Clavicle
C) Rib 2
D) Humerus

Answer: B) Clavicle

Explanation: Acromion forms AC joint with clavicle. Thus, B is correct.

7) The glenoid cavity articulates with–
A) Radius
B) Humerus
C) Ulna
D) Clavicle

Answer: B) Humerus

Explanation: Glenoid cavity receives the head of humerus forming shoulder joint. Thus, B is correct.

8) Winged scapula results from injury to which nerve?
A) Dorsal scapular nerve
B) Long thoracic nerve
C) Axillary nerve
D) Suprascapular nerve

Answer: B) Long thoracic nerve

Explanation: Injury paralyzes serratus anterior causing winging. Thus, B is correct.

9) The medial border of scapula gives attachment to–
A) Subscapularis
B) Supraspinatus
C) Serratus anterior
D) Teres major

Answer: C) Serratus anterior

Explanation: Serratus anterior inserts along medial border. Thus, C is correct.

10) Fracture of surgical neck of humerus may damage–
A) Radial nerve
B) Axillary nerve
C) Median nerve
D) Ulnar nerve

Answer: B) Axillary nerve

Explanation: Axillary nerve runs near surgical neck; injury impairs deltoid. Thus, B is correct.

11) The scapula is classified as which type of bone?
A) Long bone
B) Short bone
C) Flat bone
D) Sesamoid bone

Answer: C) Flat bone

Explanation: Scapula is a flat bone providing large muscle attachments. Thus, C is correct.

Chapter: Upper Limb Anatomy; Topic: Development of Hand; Subtopic: Ossification of Carpal Bones

Keyword Definitions:

• Carpal Bones: Eight small bones of the wrist arranged in proximal and distal rows.

• Ossification Centers: Sites where bone tissue begins to develop; carpal bones ossify postnatally.

• Capitate & Hamate: First carpal bones to ossify, appearing in the first year of life.

• Carpal Ossification Sequence: A predictable pattern used clinically to assess bone age.

• Bone Age Assessment: Radiographic evaluation comparing ossification with chronological standards.

1) Lead Question – 2016
Four carpal bones are present at what age?
A) 3 years
B) 4 years
C) 5 years
D) 6 years

Answer: A) 3 years

Explanation: Carpal bones ossify in a specific chronological sequence. Capitate and hamate appear first within the first year of life. By 2–3 years of age, two additional carpal bones typically ossify, bringing the total to four. Radiological evaluation of wrist ossification assists in assessing delayed growth or endocrine abnormalities. By this standard timeline, four ossified carpal bones are present at approximately 3 years of age, making option A the correct answer. Understanding carpal bone ossification is crucial for pediatric age estimation and orthopedic assessments.

2) Which carpal bone ossifies first?
A) Pisiform
B) Hamate
C) Capitate
D) Scaphoid

Answer: C) Capitate

Explanation: Capitate ossifies first, followed closely by hamate, both within the first year. Thus, C is correct.

3) The last carpal bone to ossify is–
A) Triquetrum
B) Pisiform
C) Lunate
D) Trapezium

Answer: B) Pisiform

Explanation: Pisiform ossifies around 9–12 years, making it the last carpal bone. Thus, B is correct.

4) A 1-year-old child's wrist x-ray commonly shows which carpal bones?
A) Capitate & hamate
B) Scaphoid & lunate
C) Trapezoid only
D) Triquetrum only

Answer: A) Capitate & hamate

Explanation: These two bones ossify first. Thus, A is correct.

5) In a 5-year-old child, the number of ossified carpal bones expected is–
A) 2
B) 4
C) 6
D) 8

Answer: C) 6

Explanation: By 5 years, about six carpal bones appear radiographically. Thus, C is correct.

6) Carpal ossification helps diagnose–
A) Diabetes mellitus
B) Growth delay
C) Pneumonia
D) Appendicitis

Answer: B) Growth delay

Explanation: Bone age assessment via carpal ossification is essential in endocrinology. Thus, B is correct.

7) Pisiform is considered a–
A) Long bone
B) Sesamoid bone
C) Flat bone
D) Irregular bone

Answer: B) Sesamoid bone

Explanation: Pisiform is a sesamoid bone within flexor carpi ulnaris tendon. Thus, B is correct.

8) Scaphoid receives blood supply mainly from–
A) Volar vessels
B) Dorsal carpal branch
C) Ulnar artery
D) Radial recurrent artery

Answer: B) Dorsal carpal branch

Explanation: Scaphoid vascularity is predominantly dorsal, explaining AVN risk. Thus, B is correct.

9) A triquetral fracture is commonly detected by–
A) MRI
B) Lateral wrist x-ray
C) Ultrasound
D) AP wrist x-ray

Answer: B) Lateral wrist x-ray

Explanation: Triquetral fractures show dorsal chip fragments best in lateral view. Thus, B is correct.

10) Carpal bone forming the floor of the anatomical snuffbox is–
A) Pisiform
B) Scaphoid
C) Hamate
D) Capitulum

Answer: B) Scaphoid

Explanation: Scaphoid lies beneath snuffbox; tenderness here suggests fracture. Thus, B is correct.

11) In children, isolated carpal fractures are rare because–
A) Carpal bones are cartilaginous
B) Radius absorbs most force
C) Ligaments are loose
D) Forearm muscles protect the wrist

Answer: A) Carpal bones are cartilaginous

Explanation: In early childhood, carpal bones are still cartilaginous and resistant to fracture. Thus, A is correct.

Chapter: Histology; Topic: Connective Tissues; Subtopic: Cartilage Types and Distribution

Keyword Definitions:

• Hyaline Cartilage: Most abundant cartilage; found in nose, trachea, bronchi, articular surfaces.

• Elastic Cartilage: Cartilage rich in elastic fibers; found in pinna, epiglottis.

• Fibrocartilage: Strongest cartilage; found in intervertebral discs and pubic symphysis.

• Chondrocytes: Cartilage cells residing in lacunae producing matrix.

• Cartilage Matrix: Extracellular material rich in type II collagen and proteoglycans.

1) Lead Question – 2016
Which is the most abundant cartilage–
A) Hyaline cartilage
B) Elastic cartilage
C) Fibrocartilage
D) None

Answer: A) Hyaline cartilage

Explanation: Hyaline cartilage is the most abundant type of cartilage in the human body. It forms the fetal skeleton, costal cartilages, articular surfaces, nasal cartilages, and supportive framework for respiratory passages. Its matrix contains type II collagen and high water content, allowing smooth movement and shock absorption. Elastic cartilage is less common and limited to flexible structures like pinna and epiglottis; fibrocartilage appears only where strength and resistance to compression are needed. Therefore, option A is correct.

2) Hyaline cartilage primarily contains which collagen type?
A) Type I
B) Type II
C) Type III
D) Type IV

Answer: B) Type II

Explanation: Hyaline cartilage matrix is dominated by type II collagen, giving it its glassy appearance and resilience. Thus, B is correct.

3) A patient with a fractured tracheal ring shows damage to which cartilage?
A) Elastic
B) Hyaline
C) Fibrocartilage
D) Calcified cartilage

Answer: B) Hyaline

Explanation: Tracheal rings are composed of hyaline cartilage, enabling airway patency. Thus, B is correct.

4) Elastic cartilage is found in which structure?
A) Articular surfaces
B) Epiglottis
C) Costal cartilage
D) Trachea

Answer: B) Epiglottis

Explanation: Epiglottis requires flexibility and contains elastic cartilage. Thus, B is correct.

5) Fibrocartilage is present in–
A) External ear
B) Nasal septum
C) Intervertebral discs
D) Laryngeal cartilages

Answer: C) Intervertebral discs

Explanation: Fibrocartilage provides tensile strength in intervertebral discs and pubic symphysis. Thus, C is correct.

6) Articular cartilage lacks–
A) Blood vessels
B) Chondrocytes
C) Matrix
D) Type II collagen

Answer: A) Blood vessels

Explanation: Articular cartilage is avascular; nutrients diffuse through synovial fluid. Thus, A is correct.

7) A child with laryngomalacia has weakness of which cartilage?
A) Elastic
B) Hyaline
C) Fibrocartilage
D) Bone cartilage

Answer: A) Elastic

Explanation: Epiglottis and arytenoid cartilages contain elastic cartilage; laxity causes laryngomalacia. Thus, A is correct.

8) Fibrocartilage differs from hyaline cartilage because it contains–
A) Type II collagen only
B) Type I collagen
C) No collagen
D) Elastic fibers

Answer: B) Type I collagen

Explanation: Fibrocartilage has abundant type I collagen for tensile strength. Thus, B is correct.

9) The perichondrium is absent in–
A) Nasal cartilage
B) Costal cartilage
C) Articular cartilage
D) Epiglottis

Answer: C) Articular cartilage

Explanation: Articular cartilage lacks perichondrium to allow smooth joint movement. Thus, C is correct.

10) Cartilage grows by which mechanism?
A) Interstitial growth
B) Appositional growth
C) Both interstitial and appositional growth
D) No growth after birth

Answer: C) Both interstitial and appositional growth

Explanation: Cartilage expands internally (interstitial) and from perichondrium (appositional). Thus, C is correct.

11) A meniscal tear involves which cartilage type?
A) Hyaline
B) Fibrocartilage
C) Elastic
D) Calcified cartilage

Answer: B) Fibrocartilage

Explanation: Knee menisci contain fibrocartilage, making B correct.

Chapter: Anatomy; Topic: Upper Limb – Axilla & Spaces; Subtopic: Quadrangular Space and Neurovascular Contents

Keyword Definitions:
• Quadrangular space: Anatomical space bordered by teres major, teres minor, long head of triceps, and humerus.
• Axillary nerve: Nerve supplying deltoid and teres minor passing through quadrangular space.
• Posterior circumflex humeral artery: Artery passing through quadrangular space supplying shoulder region.
• Teres minor: Superior boundary of quadrangular space, part of rotator cuff.
• Teres major: Inferior boundary of quadrangular space involved in arm adduction.
• Long head of triceps: Medial boundary of quadrangular space forming landmark for nerve passage.

Lead Question - 2015
What structure passes through the quadrangular space?
a) Axillary nerve
b) Radial nerve
c) Median nerve
d) Brachial artery

Explanation (Answer: a) Axillary nerve)
The axillary nerve passes through the quadrangular space along with the posterior circumflex humeral artery. It innervates the deltoid and teres minor muscles. The boundaries—teres minor above, teres major below, long head of triceps medially, and humerus laterally—define this space. Radial nerve and brachial artery do not pass through this region; they travel in different anatomical compartments.

1. Which artery accompanies the axillary nerve through the quadrangular space?
a) Anterior humeral circumflex artery
b) Radial artery
c) Posterior circumflex humeral artery
d) Deep brachial artery

Explanation (Answer: c) Posterior circumflex humeral artery)
The posterior circumflex humeral artery travels through the quadrangular space with the axillary nerve. It supplies the deltoid and shoulder joint. Its close relationship to the nerve explains why fractures of surgical neck of humerus can injure both the artery and axillary nerve. Radial and deep brachial arteries course elsewhere in the arm.

2. Injury to axillary nerve results in weakness of:
a) Elbow flexion
b) Shoulder abduction
c) Wrist extension
d) Finger adduction

Explanation (Answer: b) Shoulder abduction)
The axillary nerve innervates the deltoid muscle, which is responsible for shoulder abduction beyond 15 degrees. Injury leads to weakness in abduction, loss of deltoid contour, and numbness over lateral shoulder. It commonly occurs due to surgical neck fracture or dislocation. Other movements remain intact as their muscles are supplied by different nerves.

3. Which structure forms the medial border of quadrangular space?
a) Humerus
b) Long head of triceps
c) Teres major
d) Coracobrachialis

Explanation (Answer: b) Long head of triceps)
The long head of triceps forms the medial border of the quadrangular space. Laterally lies the humerus, superiorly teres minor, and inferiorly teres major. These boundaries are crucial during surgical exposure of axillary nerve. Understanding borders avoids iatrogenic nerve injury during deltoid or shoulder surgeries.

4. A patient with fracture of surgical neck of humerus most likely has injury to:
a) Radial nerve
b) Axillary nerve
c) Ulnar nerve
d) Musculocutaneous nerve

Explanation (Answer: b) Axillary nerve)
The axillary nerve winds around the surgical neck of humerus after passing through the quadrangular space. A fracture here easily injures the nerve and its accompanying posterior circumflex humeral artery. Symptoms include deltoid paralysis and sensory loss over shoulder. Radial nerve is more affected in mid-shaft humeral fractures.

5. Which muscle is NOT involved in forming the quadrangular space?
a) Teres major
b) Teres minor
c) Long head of triceps
d) Short head of biceps

Explanation (Answer: d) Short head of biceps)
The quadrangular space is formed by teres minor (superior), teres major (inferior), long head of triceps (medial), and humerus (lateral). Short head of biceps is located anteriorly in the arm and does not contribute to boundaries of this interval. Thus, it is not a structural component of the space.

6. A person with loss of cutaneous sensation over lateral shoulder likely has damage to:
a) Medial cutaneous nerve of arm
b) Axillary nerve
c) Radial nerve
d) Median nerve

Explanation (Answer: b) Axillary nerve)
The axillary nerve supplies the upper lateral cutaneous nerve of arm that provides sensation over the lateral shoulder. Injury produces numbness and deltoid weakness. This sensory deficit is clinically used to identify axillary nerve compression or injury. Median, radial, and ulnar nerves supply different regions of arm and forearm.

7. Axillary nerve damage may follow which type of shoulder dislocation?
a) Superior
b) Inferior
c) Posterior
d) Anterior

Explanation (Answer: d) Anterior)
Anterior shoulder dislocation is common and stretches or compresses the axillary nerve as it passes through the quadrangular space. This leads to deltoid muscle weakness and sensory loss. Posterior dislocations are less common. Inferior dislocations mostly affect brachial plexus roots rather than axillary nerve alone.

8. A tumor compressing structures in quadrangular space may affect:
a) Wrist extension
b) Forearm supination
c) Shoulder abduction
d) Finger extension

Explanation (Answer: c) Shoulder abduction)
Compression of quadrangular space affects the axillary nerve, impairing deltoid and teres minor function. This causes reduced shoulder abduction and difficulty lifting the arm. Wrist or finger functions remain intact because they are controlled by distal nerves such as radial and median nerves unaffected by compression in this region.

9. Which of the following can be palpated to assess axillary nerve function?
a) Deltoid contraction
b) Biceps tendon
c) Triceps tendon
d) Coracobrachialis contraction

Explanation (Answer: a) Deltoid contraction)
The deltoid muscle, supplied by the axillary nerve, can be palpated for contraction while the patient attempts shoulder abduction. Absence of contraction indicates nerve injury. This simple bedside assessment helps evaluate nerve integrity following humeral fractures or shoulder dislocations.

10. Which nerve passes through the triangular interval instead of quadrangular space?
a) Axillary nerve
b) Radial nerve
c) Median nerve
d) Ulnar nerve

Explanation (Answer: b) Radial nerve)
The radial nerve passes through the triangular interval along with deep brachial artery, not through quadrangular space. The triangular interval is bordered by long head of triceps, lateral head of triceps, and teres major. This anatomical separation explains why radial nerve injuries are associated with mid-shaft humerus fractures rather than shoulder injuries.

Chapter: Anatomy; Topic: Upper Limb – Hand Bones; Subtopic: Carpal Bone Articulations

Keyword Definitions:
• Pisiform: A sesamoid carpal bone that lies within the tendon of flexor carpi ulnaris.
• Triquetral: A proximal row carpal bone articulating with pisiform and hamate.
• Sesamoid bone: A bone embedded within a tendon that increases mechanical advantage.
• Flexor carpi ulnaris: A forearm muscle inserting on the pisiform, controlling wrist flexion.
• Carpal bones: Eight small bones forming wrist articulation and hand stability.
• Wrist joint: Complex joint involving radius and carpal bones enabling multi-directional wrist movement.

Lead Question - 2015
Pisiform articulates with -
a) Scaphoid
b) Trapezium
c) Triquetral
d) Lunate

Explanation (Answer: c) Triquetral)
The pisiform is a sesamoid bone located within the tendon of the flexor carpi ulnaris. It articulates only with the triquetral, making this its single articulation. Although situated superficially, it acts as a pulley to enhance FCU function. It plays no role in radiocarpal articulation and does not articulate with scaphoid, trapezium, or lunate.

1. Which carpal bone articulates with radius?
a) Pisiform
b) Hamate
c) Scaphoid
d) Triquetral

Explanation (Answer: c) Scaphoid)
The scaphoid articulates directly with the radius to form part of the radiocarpal joint. It plays a key role in wrist stability. Fractures of the scaphoid may compromise blood supply due to retrograde circulation, leading to avascular necrosis. The pisiform is not involved in radiocarpal articulation and lies anteriorly embedded in tendon.

2. Which carpal bone is most commonly fractured?
a) Lunate
b) Triquetral
c) Scaphoid
d) Pisiform

Explanation (Answer: c) Scaphoid)
The scaphoid is the most frequently fractured carpal bone, usually due to a fall on an outstretched hand. Tenderness in the anatomical snuffbox is the hallmark. Poor vascular supply makes the proximal segment prone to avascular necrosis. Pisiform rarely fractures because it is embedded within the FCU tendon and shielded.

3. A patient presents with carpal tunnel syndrome. Which bone forms the floor of the tunnel?
a) Pisiform
b) Scaphoid
c) Hamate
d) Lunate

Explanation (Answer: c) Hamate)
The hamate, along with the pisiform, hook of hamate, scaphoid, and trapezium, contributes to carpal tunnel boundaries. The floor is formed by concave arrangement of carpal bones including hamate and triquetral. Median nerve compression in this tunnel results in paresthesia in lateral digits, sparing the pisiform which lies outside the tunnel.

4. Which bone is located most medially in proximal carpal row?
a) Scaphoid
b) Lunate
c) Triquetral
d) Pisiform

Explanation (Answer: d) Pisiform)
The pisiform is the most medial carpal bone of the proximal row. Although situated anteriorly due to its sesamoid nature, it is anatomically aligned medially. It sits over the triquetral and provides leverage to FCU tendon. Its medial position is clinically significant in identifying ulnar nerve pathway through the Guyon canal.

5. Which ligament attaches to pisiform?
a) Flexor retinaculum
b) Pisohamate ligament
c) Intercarpal ligament
d) Scapholunate ligament

Explanation (Answer: b) Pisohamate ligament)
The pisohamate ligament extends from the pisiform to the hook of hamate and forms part of the roof of Guyon’s canal. This canal transmits the ulnar nerve and artery. Ligament injury may cause ulnar nerve irritation. Pisiform also serves as tendon attachment for FCU and gives origin to hypothenar muscles.

6. Which bone articulates with both scaphoid and triquetral?
a) Lunate
b) Pisiform
c) Hamate
d) Capitate

Explanation (Answer: a) Lunate)
The lunate articulates proximally with the radius and laterally with the scaphoid and medially with the triquetral. Its central position in proximal carpal row makes it vulnerable to dislocation. Lunate dislocation compresses median nerve. Pisiform does not articulate with scaphoid or lunate, only with triquetral.

7. Wrist drop occurs due to injury of which nerve?
a) Median nerve
b) Ulnar nerve
c) Radial nerve
d) Musculocutaneous nerve

Explanation (Answer: c) Radial nerve)
Wrist drop results from radial nerve injury impairing extensor muscles. The pisiform’s articulation with triquetral remains unrelated. Radial nerve palsy leads to inability to extend wrist and MCP joints. Common causes include humeral shaft fractures and compression in axilla. Sensory loss occurs on dorsum of hand excluding fingertips.

8. Guyon's canal syndrome affects which nerve?
a) Median nerve
b) Ulnar nerve
c) Radial nerve
d) Axillary nerve

Explanation (Answer: b) Ulnar nerve)
Guyon’s canal, bounded by pisiform medially and hook of hamate laterally, transmits the ulnar nerve. Compression causes numbness in medial digits and intrinsic hand weakness. Pisiform’s anatomical location is clinically significant. Cyclists may develop “handlebar palsy” due to prolonged ulnar nerve compression here.

9. A boxer suffers fracture of hook of hamate. Which structure is endangered?
a) Radial artery
b) Ulnar nerve
c) Median nerve
d) Posterior interosseous nerve

Explanation (Answer: b) Ulnar nerve)
The hook of hamate, lateral boundary of Guyon’s canal, protects the ulnar nerve and artery. Fracture jeopardizes both, leading to sensory loss in medial hand and weakness of interossei. Although pisiform articulates with triquetral, its ligamentous connections involve the hamate, explaining biomechanical linkage in injury.

10. Pain over pisiform with wrist flexion indicates irritation of which muscle?
a) FCU
b) FCR
c) ECRL
d) ECRB

Explanation (Answer: a) FCU)
The flexor carpi ulnaris (FCU) tendon inserts onto the pisiform. Pain over pisiform during wrist flexion suggests FCU tendinopathy. Since pisiform acts as sesamoid bone enhancing FCU mechanics, inflammation or overuse directly causes localized tenderness. The pain is distinct from ulnar nerve neuropathy in Guyon’s canal.

Chapter: Anatomy; Topic: Ear – Auditory Ossicles; Subtopic: Incudomalleolar and Incudostapedial Joints

Key Definitions:

• Incudomalleolar joint: A synovial saddle-type joint between the malleus and incus in the middle ear, responsible for transmitting sound vibrations from the tympanic membrane to the stapes.

• Synovial joint: A freely movable joint characterized by the presence of a joint cavity, synovial fluid, and an articular capsule.

• Saddle joint: A biaxial synovial joint where both articular surfaces are concavo-convex, allowing movement in two planes.

• Middle ear ossicles: Three small bones—malleus, incus, and stapes—that form a chain transmitting vibrations from the tympanic membrane to the oval window of the inner ear.

Lead Question (NEET PG 2015):

1. Incudomalleolar joint is a:

a) Ellipsoid joint

b) Pivot joint

c) Hinge joint

d) Saddle joint

Answer: d) Saddle joint

Explanation: The incudomalleolar joint is a synovial saddle-type joint between the body of the incus and the head of the malleus. This articulation allows limited gliding movement, transmitting and fine-tuning sound vibrations from the tympanic membrane to the stapes via the incus. Although it is a saddle joint, its motion is restricted due to the small size and tight ligaments of the ossicular chain. The other ossicular joint—the incudostapedial joint—is a ball-and-socket type synovial joint, providing slight rocking movement for efficient sound conduction to the inner ear.

Guessed Questions (Related to Auditory Ossicles and Middle Ear Joints):

2. The incudostapedial joint is classified as which type of joint?

a) Hinge joint

b) Ball and socket joint

c) Pivot joint

d) Plane joint

Answer: b) Ball and socket joint

Explanation: The incudostapedial joint is a small synovial ball and socket joint between the lenticular process of the incus and the head of the stapes. It allows a slight rocking motion, facilitating efficient transfer of sound vibrations from the incus to the stapes footplate at the oval window.

3. The stapes transmits sound vibrations to which structure of the inner ear?

a) Round window

b) Cochlear duct

c) Oval window

d) Scala tympani

Answer: c) Oval window

Explanation: The base (footplate) of the stapes fits into the oval window of the vestibule. When the stapes vibrates, it sets the perilymph of the scala vestibuli in motion, initiating the process of auditory transduction in the cochlea.

4. Clinical: Otosclerosis primarily affects which ossicle in the middle ear?

a) Malleus

b) Incus

c) Stapes

d) All equally

Answer: c) Stapes

Explanation: Otosclerosis is characterized by abnormal bone deposition around the stapes footplate, leading to fixation at the oval window and conductive hearing loss. The stapedectomy surgery replaces the stapes with a prosthesis to restore hearing.

5. The tensor tympani muscle inserts into which ossicle?

a) Stapes

b) Malleus

c) Incus

d) Tympanic membrane

Answer: b) Malleus

Explanation: The tensor tympani muscle inserts into the handle of the malleus. Its contraction increases tension on the tympanic membrane, reducing the amplitude of vibrations and protecting the inner ear from loud sounds.

6. Clinical: Damage to the facial nerve within the middle ear can affect which muscle related to hearing?

a) Tensor tympani

b) Stapedius

c) Levator veli palatini

d) Salpingopharyngeus

Answer: b) Stapedius

Explanation: The stapedius muscle, supplied by the facial nerve, stabilizes the stapes to prevent excessive movement during loud sounds. Facial nerve palsy may paralyze the stapedius, resulting in hyperacusis (increased sensitivity to sound).

7. Which ossicle directly articulates with the tympanic membrane?

a) Stapes

b) Incus

c) Malleus

d) None

Answer: c) Malleus

Explanation: The handle (manubrium) of the malleus is embedded in the tympanic membrane, transmitting vibrations from the membrane to the incus. This mechanical linkage is crucial for efficient sound energy transfer to the cochlea.

8. Clinical: A patient with tympanic membrane perforation may experience reduced vibration transmission. Which ossicle’s movement is directly affected first?

a) Incus

b) Malleus

c) Stapes

d) All equally

Answer: b) Malleus

Explanation: The malleus is directly attached to the tympanic membrane. Any perforation or scarring reduces its vibratory efficiency, thus diminishing transmission to the incus and stapes, causing conductive hearing loss.

9. The auditory ossicles develop embryologically from which pharyngeal arches?

a) First and second arches

b) Second and third arches

c) First and third arches

d) Only first arch

Answer: a) First and second arches

Explanation: The malleus and incus develop from the first pharyngeal (mandibular) arch, while the stapes arises from the second (hyoid) arch. These ossicles are derivatives of the cartilaginous elements (Meckel’s and Reichert’s cartilage) of their respective arches.

10. The main function of the ossicular chain is to:

a) Protect the tympanic membrane

b) Equalize pressure

c) Amplify and transmit sound vibrations

d) Maintain equilibrium

Answer: c) Amplify and transmit sound vibrations

Explanation: The ossicular chain acts as a mechanical lever system amplifying sound vibrations from the tympanic membrane to the oval window. The area difference between these two membranes enhances pressure transmission, optimizing sound energy conduction to the cochlea.

11. Clinical: A fracture of the temporal bone disrupting the ossicular chain results in which type of hearing loss?

a) Sensorineural

b) Conductive

c) Central

d) Mixed

Answer: b) Conductive

Explanation: Disruption of the ossicular chain (due to trauma or infection) impairs the transmission of sound from the tympanic membrane to the oval window, leading to conductive hearing loss. The inner ear structures remain intact, differentiating it from sensorineural loss.

Chapter: Embryology; Topic: Skeletal System Development; Subtopic: Ossification of Bones

Key Definitions:

• Ossification: The process by which bone tissue is formed, either by replacement of cartilage (endochondral ossification) or directly from mesenchymal tissue (intramembranous ossification).

• Intramembranous ossification: Bone development directly from mesenchymal tissue, seen in flat bones such as mandible and skull bones.

• Endochondral ossification: Bone formation by replacement of a preformed cartilage model, typical of long bones like femur and tibia.

• Mandible: The first bone to start ossifying in the human embryo, beginning around the 6th week of intrauterine life through intramembranous ossification.

Lead Question (NEET PG 2015):

1. First bone to start ossifying:

a) Femur

b) Tibia

c) Scapula

d) Mandible

Answer: d) Mandible

Explanation: The mandible is the first bone in the human body to start ossifying. It begins ossification around the 6th week of intrauterine life by intramembranous ossification, originating from the mesenchyme around Meckel’s cartilage. Although it starts early, it is not the first bone to completely ossify. The process continues postnatally, with secondary cartilaginous ossification centers appearing later. In contrast, long bones like femur and tibia ossify by endochondral ossification, beginning slightly later. Early ossification of the mandible is vital for jaw and oral cavity development.

Guessed Questions (Related to Ossification and Bone Development):

2. The type of ossification seen in flat bones like the mandible and skull bones is:

a) Endochondral ossification

b) Intramembranous ossification

c) Metaplastic ossification

d) Fibrocartilaginous ossification

Answer: b) Intramembranous ossification

Explanation: Intramembranous ossification occurs directly from mesenchymal tissue without a cartilage precursor. It is typical of flat bones such as the mandible, maxilla, and clavicle. Mesenchymal cells differentiate into osteoblasts, which secrete osteoid that later mineralizes to form bone.

3. The first long bone to start ossifying during fetal development is:

a) Humerus

b) Femur

c) Clavicle

d) Tibia

Answer: c) Clavicle

Explanation: The clavicle is the first long bone to start ossifying (around the 5th–6th week of intrauterine life), though part of it undergoes endochondral ossification. It serves as a transitional bone, having both intramembranous and endochondral ossification centers.

4. Clinical: Defective endochondral ossification results in which condition?

a) Achondroplasia

b) Osteogenesis imperfecta

c) Marfan syndrome

d) Rickets

Answer: a) Achondroplasia

Explanation: Achondroplasia is a genetic disorder caused by FGFR3 mutation, leading to defective endochondral ossification. It results in shortened long bones, normal trunk length, and characteristic dwarfism, as flat bones (formed by intramembranous ossification) remain unaffected.

5. Which cartilage acts as a precursor for mandible development?

a) Reichert’s cartilage

b) Meckel’s cartilage

c) Thyroid cartilage

d) Alar cartilage

Answer: b) Meckel’s cartilage

Explanation: The mandible develops in close association with Meckel’s cartilage derived from the first pharyngeal arch. However, the bone does not form from the cartilage itself; instead, mesenchyme around Meckel’s cartilage undergoes intramembranous ossification.

6. Clinical: In osteogenesis imperfecta, the defect lies in the synthesis of which component?

a) Type I collagen

b) Type II collagen

c) Osteocalcin

d) Elastin

Answer: a) Type I collagen

Explanation: Osteogenesis imperfecta results from a defect in type I collagen synthesis, leading to brittle bones and frequent fractures. Since type I collagen is the primary organic component of bone matrix, its deficiency impairs bone strength and resilience.

7. The secondary ossification center in long bones usually appears:

a) Before birth

b) At birth or after

c) During early fetal life

d) Only after puberty

Answer: b) At birth or after

Explanation: Secondary ossification centers typically appear at or after birth, most commonly in the epiphyses of long bones. This allows for postnatal growth in length via the epiphyseal growth plate until skeletal maturity.

8. Clinical: Premature closure of epiphyseal plates results in:

a) Gigantism

b) Achondroplasia

c) Growth retardation

d) Osteomalacia

Answer: c) Growth retardation

Explanation: Premature closure of epiphyseal growth plates halts longitudinal bone growth, resulting in short stature. It can be caused by hormonal imbalances, trauma, or genetic disorders affecting growth plate cartilage.

9. The clavicle is unique among long bones because:

a) It ossifies by endochondral process only

b) It has no secondary ossification centers

c) It ossifies first and partly by intramembranous ossification

d) It is entirely membranous in origin

Answer: c) It ossifies first and partly by intramembranous ossification

Explanation: The clavicle begins ossification earliest (around 5th–6th week IUL) and has both intramembranous (medial part) and endochondral (lateral end) ossification centers. This makes it unique among long bones.

10. The flat bones of the skull develop primarily by which type of ossification?

a) Endochondral ossification

b) Intramembranous ossification

c) Secondary ossification

d) Cartilaginous fusion

Answer: b) Intramembranous ossification

Explanation: Flat bones of the skull (frontal, parietal, occipital) develop directly from mesenchymal condensation without a cartilage model. This process ensures rapid ossification required for protection of the developing brain.

11. Clinical: Delayed closure of fontanelles in infants may indicate deficiency of:

a) Vitamin C

b) Vitamin D

c) Calcium

d) Vitamin K

Answer: b) Vitamin D

Explanation: Vitamin D deficiency impairs calcium and phosphate metabolism, leading to defective mineralization of bone matrix. In infants, this manifests as rickets with delayed fontanelle closure, widened sutures, and bone deformities.

Chapter: Thorax; Topic: Mediastinum; Subtopic: Boundaries of Mediastinum

Keyword Definitions:

• Mediastinum: The central compartment of the thoracic cavity containing the heart, great vessels, trachea, and esophagus.

• Superior Mediastinum: Upper portion of the mediastinum extending from thoracic inlet to the level of T4 vertebra.

• Thoracic Inlet: The opening at the top of the thoracic cavity bounded by the first rib, manubrium, and first thoracic vertebra.

• Transverse Thoracic Plane: An imaginary plane from the sternal angle to the intervertebral disc between T4 and T5 separating the superior and inferior mediastinum.

Lead Question – 2015

Lower limit of superior mediastinum is at which level –
a) T1
b) T4
c) T8
d) T10

Answer: b) T4

Explanation: The lower limit of the superior mediastinum corresponds to a transverse plane passing through the sternal angle to the intervertebral disc between the T4 and T5 vertebrae. This plane separates the superior and inferior mediastinum. The superior mediastinum contains major vessels like the arch of aorta, brachiocephalic veins, thymus, trachea, and esophagus.

1) Which structure is found at the level of the sternal angle?
a) Arch of aorta
b) Right atrium
c) Apex of heart
d) Pulmonary veins
Answer: a) Arch of aorta
Explanation: The sternal angle marks the level where the arch of the aorta begins and ends, and where the trachea bifurcates into bronchi. This anatomical landmark lies at the T4–T5 level, serving as an important reference point in thoracic anatomy and clinical procedures like mediastinal assessment and chest radiographs.

2) The trachea bifurcates at which vertebral level?
a) T2
b) T4–T5
c) T6
d) T8
Answer: b) T4–T5
Explanation: The tracheal bifurcation, forming the right and left main bronchi, occurs at the level of the sternal angle, corresponding to the intervertebral disc between T4 and T5. This site is clinically significant for bronchoscopy and airway management. The carina is located here and is sensitive to mechanical stimulation.

3) Which of the following structures is located in the superior mediastinum?
a) Heart
b) Thymus
c) Descending aorta
d) Pulmonary trunk
Answer: b) Thymus
Explanation: The superior mediastinum houses the thymus (especially in children), great veins, arch of aorta and its branches, trachea, esophagus, and thoracic duct. The heart and pulmonary trunk are located in the middle mediastinum. The thymus plays a role in T-cell development during early life.

4) Which vein drains into the superior vena cava within the superior mediastinum?
a) Azygos vein
b) Pulmonary vein
c) Inferior vena cava
d) Coronary sinus
Answer: a) Azygos vein
Explanation: The azygos vein ascends in the posterior thoracic wall and arches over the right lung root to drain into the superior vena cava within the superior mediastinum. This venous system forms an important collateral pathway between the superior and inferior vena cava in case of obstruction.

5) Which structure marks the superior boundary of the mediastinum?
a) Thoracic inlet
b) Sternal angle
c) Diaphragm
d) Clavicle
Answer: a) Thoracic inlet
Explanation: The thoracic inlet, bounded by the first thoracic vertebra, first rib, and manubrium, forms the upper boundary of the mediastinum. It serves as a passage for structures such as the trachea, esophagus, carotid arteries, and jugular veins entering or leaving the thoracic cavity.

6) (Clinical) A patient with a widened superior mediastinum on chest X-ray most likely has –
a) Aortic aneurysm
b) Pneumonia
c) Pneumothorax
d) Pleural effusion
Answer: a) Aortic aneurysm
Explanation: A widened superior mediastinum on chest radiograph typically indicates an aortic aneurysm or mediastinal mass. The superior mediastinum contains the aortic arch and great vessels, so aneurysmal dilatation can expand its contour. Clinical correlation and CT imaging help confirm the diagnosis and assess for rupture risk.

7) (Clinical) A stab wound at the sternal angle might damage which structure?
a) Arch of aorta
b) Left ventricle
c) Superior vena cava
d) Inferior vena cava
Answer: a) Arch of aorta
Explanation: The sternal angle marks the level where the ascending aorta becomes the arch of aorta. A penetrating injury at this level can damage the aortic arch or its branches, leading to massive hemorrhage. It’s an important reference in emergency thoracic trauma assessment.

8) (Clinical) Compression of the superior mediastinum can cause –
a) Dysphagia
b) Dyspnea
c) Venous congestion
d) All of the above
Answer: d) All of the above
Explanation: Superior mediastinal compression due to tumors or aneurysms may compress the trachea, esophagus, and veins, leading to dyspnea, dysphagia, and venous congestion (SVC syndrome). Symptoms depend on the extent of compression. Early diagnosis with CT/MRI is crucial for effective management and surgical planning.

9) The thoracic duct opens into which venous junction?
a) Right subclavian and right internal jugular
b) Left subclavian and left internal jugular
c) Brachiocephalic vein
d) Superior vena cava
Answer: b) Left subclavian and left internal jugular
Explanation: The thoracic duct drains lymph from the entire body except the right upper quadrant and empties into the venous system at the junction of the left subclavian and left internal jugular veins within the superior mediastinum. Damage here can cause chylothorax.

10) (Clinical) A tumor compressing the left recurrent laryngeal nerve in the superior mediastinum will cause –
a) Dysphagia
b) Hoarseness of voice
c) Facial paralysis
d) Stridor
Answer: b) Hoarseness of voice
Explanation: The left recurrent laryngeal nerve loops around the arch of the aorta in the superior mediastinum. Aortic aneurysm or mediastinal mass can compress this nerve, causing paralysis of vocal cords leading to hoarseness. Clinical evaluation includes laryngoscopy and imaging to locate the site of compression.

Chapter: Anatomy of Lower Limb; Topic: Hip Joint; Subtopic: Ligaments of Hip Joint

Keyword Definitions:

• Iliofemoral ligament: A strong Y-shaped ligament on the anterior surface of the hip joint that prevents hyperextension of the thigh.

• Ischiofemoral ligament: A posterior ligament that limits internal rotation and adduction of the hip joint.

• Pubofemoral ligament: A ligament that prevents excessive abduction and extension of the hip joint.

• Hip joint: A ball-and-socket synovial joint formed between the acetabulum of the pelvis and the head of the femur.

• Hyperextension: Movement beyond the normal range of extension at a joint, often prevented by strong ligaments.

Lead Question – 2015
Which of the following prevents hyperextension of thigh?
a) Ischiofemoral ligament
b) Iliofemoral ligament
c) Patellofemoral ligament
d) Puboischial ligament

Explanation: The iliofemoral ligament, also called the Y-shaped ligament of Bigelow, is the strongest ligament of the hip joint. It prevents hyperextension of the thigh during standing by maintaining upright posture without muscular effort. It runs from the anterior inferior iliac spine to the intertrochanteric line of the femur. Hence, the correct answer is b) Iliofemoral ligament.

Guessed Questions for NEET PG:

1. Which ligament of the hip joint is the strongest?
a) Ischiofemoral ligament
b) Iliofemoral ligament
c) Pubofemoral ligament
d) Transverse acetabular ligament
Explanation: The iliofemoral ligament is the strongest ligament in the human body. It resists hyperextension and stabilizes the hip during standing and walking. Its strength allows humans to maintain erect posture efficiently. Hence, the correct answer is b) Iliofemoral ligament.

2. Which ligament limits abduction and extension of the hip joint?
a) Ischiofemoral
b) Iliofemoral
c) Pubofemoral
d) Ligamentum teres
Explanation: The pubofemoral ligament lies anteroinferiorly, extending from the pubic bone to the femur, and restricts abduction and excessive extension. It reinforces the joint capsule anteriorly. Hence, the correct answer is c) Pubofemoral.

3. The ischiofemoral ligament limits which movement of the hip joint?
a) Extension
b) Adduction
c) Internal rotation
d) Flexion
Explanation: The ischiofemoral ligament spirals posteriorly from the ischium to the femur and primarily limits internal rotation and adduction. It also helps stabilize the femoral head within the acetabulum. Hence, the correct answer is c) Internal rotation.

4. Which ligament forms the Y-shaped structure at the anterior hip joint?
a) Ischiofemoral
b) Iliofemoral
c) Pubofemoral
d) Round ligament
Explanation: The iliofemoral ligament is Y-shaped and lies anteriorly. It connects the anterior inferior iliac spine with the intertrochanteric line, dividing into two limbs that resemble the letter ‘Y’. Hence, the correct answer is b) Iliofemoral ligament.

5. Clinical Case: A patient with weak iliofemoral ligament will most likely have difficulty in –
a) Standing upright
b) Flexing thigh
c) Rotating thigh
d) Abducting hip
Explanation: The iliofemoral ligament maintains erect posture by preventing hyperextension. Weakness or injury can cause difficulty in standing upright and require muscular effort for stability. Hence, the correct answer is a) Standing upright.

6. Clinical Case: During hip dislocation surgery, which ligament must be preserved to prevent hyperextension?
a) Iliofemoral
b) Ischiofemoral
c) Pubofemoral
d) Ligamentum teres
Explanation: The iliofemoral ligament prevents hyperextension; preserving it during surgery ensures hip stability in upright posture. Damage may cause postural instability or excessive extension. Hence, the correct answer is a) Iliofemoral.

7. Clinical Case: Injury to which ligament may cause excessive abduction and external rotation of hip?
a) Pubofemoral
b) Iliofemoral
c) Ischiofemoral
d) Transverse acetabular
Explanation: The pubofemoral ligament limits abduction; its injury causes uncontrolled abduction and external rotation. Hence, the correct answer is a) Pubofemoral ligament.

8. Clinical Case: A ballet dancer presents with hip instability and hyperextension. Which ligament is likely weak?
a) Pubofemoral
b) Iliofemoral
c) Ischiofemoral
d) Acetabular labrum
Explanation: Repeated overextension during ballet may overstretch the iliofemoral ligament, leading to hypermobility and anterior hip instability. Hence, the correct answer is b) Iliofemoral.

9. Clinical Case: A posterior dislocation of hip joint is prevented mainly by which ligament?
a) Iliofemoral
b) Ischiofemoral
c) Pubofemoral
d) Acetabular labrum
Explanation: The ischiofemoral ligament strengthens the posterior part of the capsule and helps prevent posterior dislocation. Hence, the correct answer is b) Ischiofemoral.

10. Clinical Case: A fracture of the acetabulum damaging the pubofemoral ligament will affect –
a) Limitation of abduction
b) Hip extension
c) Adduction
d) External rotation
Explanation: The pubofemoral ligament prevents excessive abduction and extension. Its rupture increases the range of abduction, compromising stability. Hence, the correct answer is a) Limitation of abduction.

Chapter: Osteology; Topic: Femur; Subtopic: Ossification Centers of Femur

Keyword Definitions:

• Ossification center: A site where bone tissue forms within cartilage or fibrous tissue during skeletal development.

• Secondary ossification center: It appears after birth in the epiphyses and helps in the growth of bone in length.

• Epiphysis: The end part of a long bone that grows separately from the shaft during development.

• Femur: The longest and strongest bone in the human body, extending from the hip to the knee.

• Growth plate: The cartilaginous region between the epiphysis and metaphysis responsible for bone elongation.

Lead Question – 2015
Secondary ossification center for lower end of femur?
a) Present at birth
b) Appears at 6 months of age
c) Appears at 1 year of age
d) Appears at 5 years of age

Explanation: The secondary ossification center for the lower end of the femur is unique because it is present at birth. This ossification center is used in forensic and radiological assessment to determine fetal viability and neonatal maturity. The lower femoral epiphysis ossifies before birth, while the upper one appears after 3–6 months. Hence, the correct answer is a) Present at birth.

Guessed Questions for NEET PG:

1. The primary ossification center of the femur appears at –
a) 7th week of intrauterine life
b) 5th month of intrauterine life
c) At birth
d) 6 months after birth
Explanation: The primary ossification center for the femoral shaft appears around the 7th week of intrauterine life. It forms the diaphysis, contributing to the bone’s early development and strength. Hence, the correct answer is a) 7th week of intrauterine life.

2. The secondary ossification center for the head of femur appears at –
a) Birth
b) 1 year
c) 3 years
d) 5 years
Explanation: The secondary ossification center for the head of femur appears around the first year after birth. It later fuses with the shaft during adolescence (around 18–20 years). Hence, the correct answer is b) 1 year.

3. The fusion of the lower end of femur occurs at –
a) 14 years
b) 16 years
c) 18 years
d) 20 years
Explanation: The lower end of the femur fuses with the shaft around 18–20 years of age. This fusion marks the end of longitudinal bone growth. Hence, the correct answer is d) 20 years.

4. Which of the following bones shows a secondary ossification center at birth?
a) Lower end of femur
b) Upper end of tibia
c) Lower end of humerus
d) Clavicle
Explanation: The lower end of femur and upper end of tibia are two long bones showing secondary ossification centers at birth. Among the options, the femur is most characteristic. Hence, the correct answer is a) Lower end of femur.

5. Radiograph showing an ossification center at the lower end of femur indicates –
a) Stillbirth
b) Viable fetus
c) Premature fetus
d) None
Explanation: The presence of an ossification center at the lower femoral epiphysis indicates fetal maturity and viability (>36 weeks). It helps in medico-legal determination of live birth. Hence, the correct answer is b) Viable fetus.

6. Clinical Case: A newborn X-ray shows ossification at lower end of femur. What does it signify?
a) The baby is at least 36 weeks old
b) Premature birth
c) Skeletal dysplasia
d) Delayed ossification
Explanation: The lower femoral epiphysis ossification appears around 36 weeks of intrauterine life. Hence, its presence in a newborn confirms term maturity. The correct answer is a) The baby is at least 36 weeks old.

7. Clinical Case: In a child, a fracture through the metaphysis of the distal femur can damage –
a) Epiphyseal plate
b) Articular cartilage
c) Primary ossification center
d) Periosteum only
Explanation: The metaphysis lies adjacent to the growth plate. A fracture here may disrupt the epiphyseal plate, leading to growth disturbances. Hence, the correct answer is a) Epiphyseal plate.

8. Clinical Case: A term infant shows absence of ossification at distal femur. This suggests –
a) Preterm delivery
b) Post-term infant
c) Nutritional deficiency
d) Skeletal anomaly
Explanation: The absence of ossification in the distal femoral epiphysis at birth indicates that the infant is preterm (less than 36 weeks gestation). Thus, the correct answer is a) Preterm delivery.

9. Clinical Case: A 2-year-old child suffers from septic arthritis of the knee. Which part of femur is likely affected?
a) Lower end epiphysis
b) Shaft
c) Upper end epiphysis
d) Metaphysis
Explanation: Infection from the knee joint can spread to the lower end epiphysis of the femur due to its proximity. In young children, the metaphyseal vessels communicate with the epiphysis, allowing such spread. Hence, the correct answer is a) Lower end epiphysis.

10. Clinical Case: In forensic examination, presence of distal femoral epiphyseal ossification center indicates –
a) Infant viability
b) Skeletal deformity
c) Postnatal infection
d) Nutritional rickets
Explanation: The distal femoral ossification center is a reliable indicator of fetal viability and term maturity. Its presence in autopsy or radiograph confirms that the fetus had reached full term before death. The correct answer is a) Infant viability.

Chapter: Lower Limb Anatomy; Topic: Knee Joint; Subtopic: Ligaments of Knee Joint and Clinical Correlations

Keyword Definitions:

• ACL (Anterior Cruciate Ligament): Prevents anterior displacement of the tibia on the femur; most commonly injured ligament in the knee.

• PCL (Posterior Cruciate Ligament): Prevents posterior displacement of the tibia on the femur; stronger than ACL.

• MCL (Medial Collateral Ligament): Resists valgus stress; often injured along with medial meniscus.

• LCL (Lateral Collateral Ligament): Resists varus stress; not attached to the lateral meniscus.

• Knee Joint: A synovial hinge joint between femur, tibia, and patella; allows flexion, extension, and slight rotation.

Lead Question - 2015

Most common ligament damaged in knee injury is
a) ACL
b) PCL
c) MCL
d) LCL

Explanation: The anterior cruciate ligament (ACL) is the most commonly injured ligament of the knee. It prevents anterior translation of the tibia on the femur. ACL injury usually occurs due to sudden deceleration, twisting, or hyperextension during sports. It presents with knee instability and positive Lachman and anterior drawer tests. (Answer: a)

1) Which test is used to assess the integrity of the ACL?
a) Lachman test
b) Posterior drawer test
c) McMurray test
d) Pivot shift test

Explanation: The Lachman test is the most sensitive test for ACL injury. It involves pulling the tibia forward while stabilizing the femur to assess anterior translation. Increased forward movement indicates ACL tear. The pivot shift test also checks for rotational instability caused by ACL deficiency. (Answer: a)

2) Which ligament prevents posterior displacement of the tibia on the femur?
a) ACL
b) PCL
c) MCL
d) LCL

Explanation: The posterior cruciate ligament (PCL) prevents posterior displacement of the tibia relative to the femur. It is stronger than the ACL and is commonly injured in dashboard-type car accidents where the tibia is forced backward. (Answer: b)

3) A football player sustains a blow to the lateral side of the knee. Which structures are likely injured?
a) MCL, medial meniscus, ACL
b) LCL and lateral meniscus
c) PCL and popliteus
d) Quadriceps tendon

Explanation: A blow to the lateral side of the knee stretches the medial side, resulting in injury to the medial collateral ligament (MCL), often accompanied by damage to the medial meniscus and ACL—known as the “unhappy triad” injury pattern. (Answer: a)

4) Which ligament of the knee is attached to the lateral meniscus?
a) ACL
b) PCL
c) MCL
d) LCL

Explanation: The lateral meniscus is not attached to the lateral collateral ligament (LCL). Instead, it is connected to the popliteus tendon, which helps prevent injury. The medial meniscus, however, is firmly attached to the MCL, predisposing it to injury. (Answer: d)

5) Which ligament prevents excessive valgus stress at the knee joint?
a) MCL
b) LCL
c) ACL
d) PCL

Explanation: The medial collateral ligament (MCL) resists valgus stress, which pushes the knee medially. Injury occurs with lateral impact or twisting forces, commonly during football or skiing accidents. It is often associated with medial meniscus and ACL injury. (Answer: a)

6) A 25-year-old athlete hears a “pop” in the knee followed by swelling and instability. Which ligament is most likely torn?
a) ACL
b) PCL
c) MCL
d) LCL

Explanation: A “popping” sound followed by rapid swelling and instability is classic for ACL tear. It often occurs after sudden deceleration or change in direction during sports. Diagnosis is confirmed by MRI or positive Lachman test. (Answer: a)

7) A patient involved in a car accident presents with posterior sagging of the tibia. Which ligament is most likely injured?
a) ACL
b) PCL
c) MCL
d) LCL

Explanation: Posterior sagging of the tibia in a flexed knee indicates a PCL injury. It commonly occurs in dashboard injuries where the tibia strikes the dashboard, forcing it posteriorly. The posterior drawer test helps confirm this diagnosis. (Answer: b)

8) The “unhappy triad” of knee injury includes damage to which three structures?
a) ACL, MCL, Medial meniscus
b) PCL, LCL, Lateral meniscus
c) ACL, LCL, Lateral meniscus
d) PCL, MCL, Medial meniscus

Explanation: The classic unhappy triad involves tears of the ACL, MCL, and medial meniscus. It occurs when a lateral blow to the knee causes valgus stress. This triad leads to instability, pain, and swelling, requiring surgical repair in many cases. (Answer: a)

9) The tibial collateral ligament is also known as
a) Medial collateral ligament
b) Lateral collateral ligament
c) Posterior cruciate ligament
d) Oblique popliteal ligament

Explanation: The tibial collateral ligament is another name for the medial collateral ligament (MCL). It extends from the medial epicondyle of the femur to the medial condyle and shaft of the tibia, providing medial knee stability. (Answer: a)

10) A basketball player presents with knee instability during pivoting movements. Which ligament injury is most likely?
a) ACL
b) PCL
c) MCL
d) LCL

Explanation: Instability during pivoting or twisting is characteristic of an ACL tear. The ACL provides anterior and rotational stability to the knee. Damage results in “giving way” sensations during direction changes, requiring rehabilitation or surgical reconstruction. (Answer: a)

Chapter: Gross Anatomy; Topic: Lower Limb; Subtopic: Femoral Triangle

Keyword Definitions:
• Femoral Triangle: A triangular space on the anterior aspect of the upper thigh bounded by the inguinal ligament, sartorius, and adductor longus.
• Sartorius: Longest muscle of the body forming the lateral boundary of the femoral triangle.
• Adductor Longus: Forms the medial boundary and part of the floor.
• Femoral Vessels: Major artery and vein supplying the lower limb.
• Inguinal Ligament: Upper boundary of the femoral triangle.

Lead Question – 2015
All are true about femoral triangle, EXCEPT?
a) Lateral margin is formed by sartorius
b) Floor is formed by adductor longus
c) Contains the femoral vessels
d) None of the above

Explanation: The femoral triangle is bounded laterally by the sartorius, medially by adductor longus, and superiorly by the inguinal ligament. Its floor is formed by iliopsoas and pectineus muscles, not adductor longus. It contains the femoral nerve, artery, and vein arranged laterally to medially. Answer: (b) Floor is formed by adductor longus.

1. Which of the following structures forms the medial boundary of the femoral triangle?
a) Sartorius
b) Adductor longus
c) Inguinal ligament
d) Rectus femoris
Explanation: The medial boundary of the femoral triangle is formed by the adductor longus muscle, while the lateral boundary is formed by sartorius. The inguinal ligament forms the base. Understanding these boundaries is essential in locating the femoral pulse during clinical examination. Answer: (b) Adductor longus.

2. Which structure lies most lateral in the femoral triangle?
a) Femoral nerve
b) Femoral artery
c) Femoral vein
d) Femoral canal
Explanation: In the femoral triangle, the arrangement from lateral to medial is “NAVEL” – Nerve, Artery, Vein, Empty space, and Lymphatics. The femoral nerve is therefore the most lateral structure. This arrangement helps in performing femoral nerve blocks. Answer: (a) Femoral nerve.

3. Which muscle forms the floor of the femoral triangle medially?
a) Iliacus
b) Pectineus
c) Adductor brevis
d) Sartorius
Explanation: The floor of the femoral triangle is formed by the iliopsoas laterally and pectineus medially. These muscles provide support to the femoral artery and vein that lie above them. The adductor longus contributes to the medial boundary, not the floor. Answer: (b) Pectineus.

4. The femoral sheath encloses all of the following EXCEPT:
a) Femoral artery
b) Femoral vein
c) Femoral nerve
d) Femoral canal
Explanation: The femoral sheath is a funnel-shaped fascial sleeve enclosing the femoral artery, femoral vein, and femoral canal but not the femoral nerve. This anatomical distinction is important in surgeries and hernia diagnosis. Answer: (c) Femoral nerve.

5. Which of the following best describes the clinical importance of the femoral triangle?
a) Site for venous sampling
b) Site for arterial catheterization
c) Both a and b
d) None
Explanation: The femoral triangle provides easy access to major vessels for procedures like arterial catheterization, femoral pulse palpation, and venous sampling. It is a key anatomical landmark for clinicians and surgeons due to its superficial vascular location. Answer: (c) Both a and b.

6. A 55-year-old male undergoing cardiac catheterization through the femoral artery—where should the puncture be made?
a) Below the inguinal ligament
b) Above the inguinal ligament
c) At mid-thigh
d) Near adductor canal
Explanation: The ideal puncture site for femoral artery access is just below the inguinal ligament within the femoral triangle. Puncturing above it risks retroperitoneal bleeding, while lower punctures may cause pseudoaneurysms. Answer: (a) Below the inguinal ligament.

7. A trauma patient with groin swelling after catheterization likely has damage to:
a) Femoral vein
b) Femoral nerve
c) Femoral artery
d) Deep femoral artery
Explanation: Groin swelling post-catheterization suggests hematoma from femoral artery injury. The artery’s superficial location in the femoral triangle makes it prone to iatrogenic damage. Ultrasound guidance helps prevent such complications. Answer: (c) Femoral artery.

8. Femoral hernia passes through which structure?
a) Femoral canal
b) Adductor canal
c) Obturator canal
d) Popliteal fossa
Explanation: A femoral hernia protrudes through the femoral canal, which is the medial compartment of the femoral sheath. It is more common in females due to a wider pelvis and can cause bowel strangulation if untreated. Answer: (a) Femoral canal.

9. In a femoral nerve block, the local anesthetic should be injected:
a) Lateral to femoral artery
b) Medial to femoral vein
c) Within the femoral sheath
d) Into adductor canal
Explanation: The femoral nerve lies lateral to the femoral artery and outside the femoral sheath. Therefore, local anesthetic is injected lateral to the artery to block the nerve effectively for lower limb surgeries. Answer: (a) Lateral to femoral artery.

10. The apex of the femoral triangle is formed by the meeting of:
a) Sartorius and adductor longus
b) Inguinal ligament and adductor longus
c) Sartorius and rectus femoris
d) Adductor longus and pectineus
Explanation: The apex of the femoral triangle is formed where sartorius crosses the adductor longus muscle. This apex continues as the adductor canal, transmitting vessels to the popliteal fossa. Answer: (a) Sartorius and adductor longus.

Chapter: Lower Limb Anatomy; Topic: Foot Joints; Subtopic: Movements at Subtalar and Midtarsal Joints

Keyword Definitions:

• Abduction of Foot: Movement of the forefoot away from the midline of the body, occurring mainly at the subtalar and midtarsal joints.

• Adduction of Foot: Movement of the forefoot toward the midline of the body, also involving subtalar and transverse tarsal joints.

• Subtalar Joint: The articulation between the talus and calcaneus bones, permitting inversion, eversion, abduction, and adduction movements.

• Midtarsal (Transverse Tarsal) Joint: Formed by talonavicular and calcaneocuboid joints, it assists subtalar joint in complex foot movements.

Lead Question (2015):
Abduction and adduction of foot occurs at which joints?
a) Ankle
b) Subtalar
c) Tarso-metatarsal
d) None

Explanation: The Subtalar joint is responsible for abduction and adduction of the foot. These movements occur as part of the complex inversion and eversion actions of the foot. The subtalar joint between the talus and calcaneus permits the rotation of the foot around an oblique axis, essential for adaptation to uneven ground during gait and balance maintenance.

Guessed Questions:

1. Inversion and eversion of the foot primarily occur at which joint?
a) Subtalar joint
b) Ankle joint
c) Metatarsophalangeal joint
d) Intertarsal joint
Explanation: The Subtalar joint is primarily responsible for inversion and eversion of the foot. This joint allows the foot to adjust to irregular surfaces and contributes to shock absorption during walking. Inversion turns the sole medially, while eversion turns it laterally, maintaining stability and balance during locomotion.

2. Dorsiflexion and plantarflexion occur mainly at which joint?
a) Ankle joint
b) Subtalar joint
c) Tarso-metatarsal joint
d) Interphalangeal joint
Explanation: The Ankle joint (talocrural joint) allows dorsiflexion and plantarflexion of the foot. It is a hinge-type synovial joint formed between the distal tibia, fibula, and talus. Dorsiflexion raises the foot upwards, while plantarflexion points the toes downward, essential for walking, running, and jumping activities.

3. (Clinical) A patient with subtalar arthritis will have difficulty performing which movement?
a) Inversion and eversion
b) Dorsiflexion
c) Plantarflexion
d) Toe extension
Explanation: The Subtalar joint enables inversion and eversion of the foot. In subtalar arthritis, these movements become painful and restricted, making it difficult to walk on uneven surfaces. The joint’s oblique axis movement is compromised, leading to stiffness and imbalance in gait correction during locomotion.

4. The subtalar joint is formed between which bones?
a) Talus and calcaneus
b) Talus and navicular
c) Calcaneus and cuboid
d) Navicular and cuboid
Explanation: The Subtalar joint is formed between the inferior surface of the talus and the superior surface of the calcaneus. It is a synovial joint that allows complex rotatory movements, including inversion, eversion, abduction, and adduction. It provides adaptability and mobility to the foot during locomotion.

5. (Clinical) Which joint injury limits walking on uneven ground the most?
a) Subtalar joint
b) Ankle joint
c) Metatarsophalangeal joint
d) Knee joint
Explanation: Injury to the Subtalar joint significantly limits the ability to walk on uneven surfaces because inversion and eversion occur here. These movements adjust the foot position during gait. Loss of subtalar movement results in rigid foot mechanics, poor shock absorption, and instability during side-to-side movements.

6. The transverse tarsal joint includes which of the following?
a) Talonavicular and calcaneocuboid joints
b) Talocalcaneal and naviculocuboid joints
c) Ankle and talonavicular joints
d) Tarsometatarsal joints
Explanation: The Transverse tarsal joint consists of the talonavicular and calcaneocuboid joints. These joints together enhance the range of inversion and eversion. They help maintain foot flexibility and stability during walking, running, and balancing on uneven terrains. This joint acts with the subtalar joint for smooth foot movements.

7. (Clinical) Which joint is involved in clubfoot deformity correction?
a) Subtalar joint
b) Ankle joint
c) Tarso-metatarsal joint
d) Interphalangeal joint
Explanation: The Subtalar joint is primarily corrected during treatment of clubfoot (talipes equinovarus). In this congenital deformity, the foot is inverted and plantarflexed due to abnormal subtalar alignment. Gradual manipulation and casting (Ponseti method) help restore normal subtalar joint positioning for proper foot orientation and walking ability.

8. (Clinical) A fall from height causing inversion injury damages which joint first?
a) Subtalar joint
b) Ankle joint
c) Tarso-metatarsal joint
d) Interphalangeal joint
Explanation: Inversion injuries often affect the Subtalar joint due to the sudden medial rotation of the foot. The interosseous talocalcaneal ligament is frequently strained. Such injuries cause pain below the lateral malleolus, difficulty in eversion, and tenderness over the subtalar region, commonly misdiagnosed as ankle sprains.

9. Which ligament maintains stability of the subtalar joint?
a) Interosseous talocalcaneal ligament
b) Deltoid ligament
c) Plantar calcaneonavicular ligament
d) Long plantar ligament
Explanation: The Interosseous talocalcaneal ligament is the key stabilizer of the subtalar joint. It lies within the tarsal canal between the talus and calcaneus, preventing excessive inversion and eversion. Damage to this ligament can cause chronic subtalar instability and abnormal movement patterns during gait.

10. (Clinical) A fracture of the calcaneus most severely affects which joint?
a) Subtalar joint
b) Ankle joint
c) Tarso-metatarsal joint
d) Midtarsal joint
Explanation: The Subtalar joint is most affected in calcaneal fractures because it articulates with the superior talus. Fracture disruption leads to post-traumatic arthritis, restricted inversion-eversion, and chronic heel pain. CT imaging helps in diagnosis. Treatment may include surgical fixation to restore the subtalar articular surface alignment and movement.

Chapter: Anatomy; Topic: Joints; Subtopic: Innervation of Joints

Keyword Definitions:

• Synovium: Thin membrane lining the joint capsule producing synovial fluid.

• Capsule: Fibrous tissue enclosing the joint for stability and protection.

• Articular cartilage: Smooth avascular tissue covering bone ends to reduce friction.

• Ligaments: Connective tissues joining bones to stabilize the joint.

• Joint innervation: Supply of nerves to joint structures transmitting pain and proprioception.

Lead Question - 2014

Innervated structures of joints are all except ?
a) Synovium
b) Capsule
c) Articular cartilage
d) Ligaments

Explanation: Articular cartilage is avascular and non-innervated, meaning it lacks both blood vessels and nerve endings. In contrast, the capsule, synovium, and ligaments have rich nerve supplies that convey pain and proprioceptive signals. Therefore, the correct answer is Articular cartilage, which relies on diffusion for nutrition and repair due to absence of nerves and vessels.

1) Pain sensation from the hip joint is carried mainly by:
a) Obturator nerve
b) Sciatic nerve
c) Femoral nerve
d) All of the above

Explanation: The hip joint receives sensory innervation from multiple nerves, including the obturator, femoral, and sciatic nerves. These nerves transmit pain and proprioceptive sensations. Hence, the correct answer is All of the above. Such extensive innervation ensures effective joint protection and reflexive muscular stabilization during movement or injury.

2) Which structure provides proprioceptive feedback from a joint?
a) Articular cartilage
b) Synovium
c) Capsule and ligaments
d) Synovial fluid

Explanation: Proprioception from joints originates mainly from mechanoreceptors present in the joint capsule and ligaments. These receptors sense stretch, position, and movement. Articular cartilage lacks such receptors. Thus, the correct answer is Capsule and ligaments. This feedback system is crucial for coordinated movement and joint stability during locomotion or external stress.

3) Referred pain from the shoulder joint may be felt in:
a) Arm
b) Neck
c) Scapular region
d) All of the above

Explanation: Shoulder joint pain is often referred to the neck, arm, and scapular region due to overlapping nerve supply through the C5–C6 spinal segments. Hence, the correct answer is All of the above. Referred pain reflects the convergence of sensory fibers in the spinal cord from multiple anatomical regions sharing a common root level.

4) Which joint structure has no sensory nerve endings?
a) Ligaments
b) Articular cartilage
c) Capsule
d) Synovium

Explanation: The articular cartilage has no sensory nerve endings, making it insensitive to pain. Damage to cartilage thus presents late clinically. Other structures like ligaments and capsule are richly innervated. Therefore, the correct answer is Articular cartilage. This lack of innervation contributes to painless degeneration in conditions like osteoarthritis until secondary involvement occurs.

5) Which nerve supplies the posterior capsule of the knee joint?
a) Femoral nerve
b) Tibial nerve
c) Common peroneal nerve
d) Saphenous nerve

Explanation: The posterior capsule of the knee joint is supplied by the tibial nerve, which carries sensory and proprioceptive fibers. The femoral and saphenous nerves supply anterior and medial regions respectively. Hence, the correct answer is Tibial nerve. This pattern helps localize knee joint pathology based on pain distribution during clinical examination.

6) A 40-year-old man with knee trauma feels deep joint pain without swelling. Which structure is most likely injured?
a) Capsule
b) Articular cartilage
c) Synovium
d) Ligament

Explanation: Deep pain without inflammation suggests damage to the capsule or ligaments rather than synovium. However, since the capsule carries dense pain receptors, the correct answer is Capsule. Articular cartilage injury usually causes mechanical symptoms. Capsule injury leads to dull, aching pain due to stretch or microtears of the fibrous tissue.

7) During arthroscopy, synovial inflammation causes severe pain due to:
a) Rich vascularity and nerve endings
b) Lack of blood vessels
c) Presence of cartilage
d) Presence of fat pads

Explanation: Synovium is highly vascular and innervated, making inflammation extremely painful. The correct answer is Rich vascularity and nerve endings. This explains why synovitis in rheumatoid arthritis leads to intense pain and tenderness. The vascular network facilitates immune cell infiltration and swelling, worsening the pain during joint motion or pressure.

8) Referred pain from hip joint disease is felt over:
a) Knee
b) Ankle
c) Groin
d) Both a and c

Explanation: Hip joint pain is often referred to the knee and groin through the obturator and femoral nerves (L2–L4). Hence, the correct answer is Both a and c. This overlap occurs because these nerves share spinal roots supplying both joints. Therefore, knee pain may occasionally represent underlying hip pathology rather than local knee disease.

9) Which joint structure is responsible for pain in osteoarthritis?
a) Articular cartilage
b) Subchondral bone and capsule
c) Synovial fluid
d) Meniscus

Explanation: Pain in osteoarthritis arises from the subchondral bone, synovium, and capsule — all innervated tissues. The correct answer is Subchondral bone and capsule. Cartilage degeneration exposes nerve-rich bone leading to deep aching pain. Synovial inflammation adds to the discomfort, making these structures major pain contributors in degenerative joint disease.

10) A patient with rheumatoid arthritis experiences joint tenderness mainly due to:
a) Articular cartilage erosion
b) Synovial inflammation
c) Meniscal tear
d) Ligament laxity

Explanation: Tenderness in rheumatoid arthritis is due to inflammation of the synovium which is richly supplied with pain fibers. Hence, the correct answer is Synovial inflammation. Synovial proliferation (pannus) invades cartilage and bone, but pain originates from the vascular, innervated synovium — the primary site of autoimmune inflammation in rheumatoid arthritis.

Chapter: Anatomy; Topic: Joints of Thorax; Subtopic: Sternochondral Joints

Keyword Definitions:

• Joint: The site where two bones meet, allowing movement or providing stability.

• Cartilaginous joint: Bones united by cartilage, allowing limited movement.

• Primary cartilaginous joint (synchondrosis): Joined by hyaline cartilage, usually immovable.

• Secondary cartilaginous joint (symphysis): Has fibrocartilage, allows limited movement.

• Synovial joint: Freely movable joint surrounded by a capsule filled with synovial fluid.

• Sternochondral joint: Articulation between the sternum and costal cartilages.

Lead Question – 2014

Sternochondral joint is?
a) Primary cartilaginous
b) Secondary cartilaginous
c) Fibrous
d) Synovial

Explanation:
The sternochondral joints are between the costal cartilages and sternum. The first sternochondral joint is a primary cartilaginous (synchondrosis) joint, while the 2nd to 7th are synovial joints allowing slight gliding movement during respiration. This mixed type of articulation ensures stability with flexibility in thoracic expansion. Answer: Synovial (except 1st – primary cartilaginous).

1) The first sternochondral joint differs from the others because it is:
a) Synovial
b) Primary cartilaginous
c) Secondary cartilaginous
d) Fibrous
Explanation: The first sternochondral joint is a primary cartilaginous (synchondrosis) joint composed of hyaline cartilage, allowing no movement. It provides firm attachment of the first rib to the sternum for stability during respiration. Answer: Primary cartilaginous.

2) The 2nd to 7th sternochondral joints are:
a) Primary cartilaginous
b) Secondary cartilaginous
c) Synovial plane joints
d) Fibrous joints
Explanation: The 2nd–7th sternochondral joints are synovial plane type joints that allow gliding movements. These joints assist in the expansion and contraction of the thoracic cage during breathing. Answer: Synovial plane joints.

3) Clinical Case: A patient with ankylosis of sternochondral joints will have difficulty in:
a) Neck movement
b) Breathing
c) Arm movement
d) Swallowing
Explanation: Ankylosis (fusion) of sternochondral joints restricts thoracic cage expansion, reducing respiratory efficiency. The patient experiences breathing difficulty due to limited rib movement during inspiration. Answer: Breathing.

4) Which joint type unites manubrium and body of sternum?
a) Primary cartilaginous
b) Secondary cartilaginous
c) Synovial
d) Fibrous
Explanation: The manubriosternal joint is a secondary cartilaginous (symphysis) joint composed of fibrocartilage. It provides slight movement during respiration and marks the sternal angle (of Louis). Answer: Secondary cartilaginous.

5) Clinical Case: Pain and tenderness over sternochondral joints may be due to:
a) Costochondritis
b) Osteoporosis
c) Rib fracture
d) Pleural effusion
Explanation: Costochondritis is inflammation of the sternochondral junctions, causing localized anterior chest wall pain. It is benign and self-limiting, often mimicking cardiac chest pain. Answer: Costochondritis.

6) Which rib’s costal cartilage articulates with the manubriosternal joint?
a) 1st rib
b) 2nd rib
c) 3rd rib
d) 4th rib
Explanation: The 2nd costal cartilage articulates at the manubriosternal joint (sternal angle). This landmark is clinically important for rib counting and correlates with the level of the aortic arch and T4 vertebra. Answer: 2nd rib.

7) Clinical Case: A 55-year-old man presents with chest pain localized to the costosternal junction, worse on movement. Most likely cause?
a) Angina pectoris
b) Costochondritis
c) Rib fracture
d) Pleural effusion
Explanation: Localized tenderness and pain on movement without cardiac symptoms indicate costochondritis, an inflammation of the costosternal or sternochondral junctions. Answer: Costochondritis.

8) Which joint helps in the expansion of the chest during inspiration?
a) Costovertebral joint
b) Sternochondral joint
c) Manubriosternal joint
d) Xiphisternal joint
Explanation: The sternochondral joints, especially from 2nd to 7th ribs, allow gliding movements that facilitate chest expansion during inspiration. Answer: Sternochondral joint.

9) The xiphisternal joint becomes ossified at what age?
a) 20 years
b) 30 years
c) 40 years
d) After 40 years
Explanation: The xiphisternal joint, a primary cartilaginous type, ossifies completely by around 40 years. It marks the lower end of the sternal body and the level of T9 vertebra. Answer: After 40 years.

10) Clinical Case: Post-thoracotomy patient has limited chest expansion due to stiff joints at costosternal junction. Type of joint affected?
a) Synovial plane
b) Primary cartilaginous
c) Secondary cartilaginous
d) Fibrous
Explanation: The 2nd–7th sternochondral joints are synovial plane joints. Fibrosis or inflammation in these joints limits thoracic expansion and impairs ventilation. Answer: Synovial plane.

Chapter: Anatomy; Topic: Osteology; Subtopic: Secondary Ossification Centers of Long Bones

Keyword Definitions:

• Ossification center: Area where bone formation begins during development.

• Primary ossification center: Appears first, usually in the diaphysis (shaft) of long bones.

• Secondary ossification center: Appears later, usually at the epiphysis (ends) of long bones.

• Epiphysis: The rounded ends of a long bone where growth occurs.

• Femur: The longest and strongest bone of the human body, forming the thigh.

Lead Question – 2014

Secondary ossification center for lower end of femur?
a) Present at birth
b) Appears at 6 months of age
c) Appears at 1 year of age
d) Appears at 5 years of age

Explanation:
The lower end of femur shows a secondary ossification center that is present at birth. It is one of the earliest secondary centers to appear and serves as a useful indicator for assessing fetal viability in late pregnancy. Its early appearance helps in estimating gestational age radiologically. Answer: Present at birth.

1) The secondary ossification center for the head of femur appears at:
a) Birth
b) 1 year
c) 5 years
d) Puberty
Explanation: The secondary ossification center for the head of femur appears at about 1 year of age and fuses by 18–20 years. It contributes to the growth of the proximal end of the femur and helps maintain the hip joint’s structural integrity. Answer: 1 year.

2) The secondary ossification center for upper end of tibia appears at:
a) Birth
b) 1 year
c) 3 years
d) 5 years
Explanation: The upper end of the tibia develops a secondary ossification center around birth. This site contributes to longitudinal bone growth and is radiologically visible early in life, aiding in age estimation. Answer: Birth.

3) Clinical Case: A newborn X-ray shows an ossification center at distal femur. What does it indicate?
a) Prematurity
b) Full-term baby
c) Skeletal dysplasia
d) Growth delay
Explanation: The presence of a distal femoral ossification center indicates a full-term baby (around 36–38 weeks gestation). Its absence in preterm infants helps assess maturity in forensic and neonatal evaluation. Answer: Full-term baby.

4) Which long bone shows a secondary ossification center appearing before birth?
a) Femur (lower end)
b) Humerus (head)
c) Radius (lower end)
d) Tibia (upper end)
Explanation: The lower end of femur and upper end of tibia are exceptions where secondary ossification centers appear before birth, unlike most long bones. They are used to determine fetal maturity radiologically. Answer: Femur (lower end).

5) Clinical Case: A 10-year-old child fractures the lower end of femur. Which part of bone growth may be affected?
a) Primary ossification center
b) Secondary ossification center
c) Diaphyseal growth plate
d) Epiphyseal cartilage
Explanation: In such fractures, the epiphyseal cartilage (growth plate) near the secondary ossification center may be damaged. This can impair longitudinal growth and cause limb length discrepancy if not properly aligned. Answer: Epiphyseal cartilage.

6) The secondary ossification center for upper end of humerus appears at:
a) Birth
b) 6 months
c) 1 year
d) 3 years
Explanation: The upper end of humerus develops its secondary ossification center at birth. It has two centers — one for the head and another for the greater tubercle, which later fuse. Answer: Birth.

7) Clinical Case: In a neonate, absence of distal femoral ossification center indicates:
a) Full-term gestation
b) Premature birth
c) Congenital femoral hypoplasia
d) Nutritional deficiency
Explanation: Absence of the distal femoral ossification center in a neonate indicates premature birth. It usually appears at around 36 weeks of intrauterine life and serves as a radiologic sign of maturity. Answer: Premature birth.

8) The last secondary ossification center to fuse in the femur is at:
a) Lower end
b) Upper end
c) Head
d) Greater trochanter
Explanation: The head of the femur is the last to fuse, typically by 18–20 years of age. This timing helps in assessing skeletal maturity during forensic and orthopedic evaluation. Answer: Head.

9) Clinical Case: A radiograph shows early fusion of epiphyseal plates at both ends of femur. This may result from:
a) Hypothyroidism
b) Hyperthyroidism
c) Hypogonadism
d) Precocious puberty
Explanation: Early fusion of growth plates occurs in precocious puberty due to premature exposure to sex hormones. This causes stunted growth as bone elongation stops early. Answer: Precocious puberty.

10) Secondary ossification center for greater trochanter appears at:
a) Birth
b) 4 years
c) 10 years
d) 15 years
Explanation: The greater trochanter of the femur develops its secondary ossification center at about 4 years of age. This center fuses later in adolescence. Its appearance pattern helps identify bone age in radiographic studies. Answer: 4 years.

Chapter: Respiratory System Anatomy; Topic: Larynx; Subtopic: Cartilages of Larynx

Keyword Definitions:

• Larynx: A cartilaginous structure located in the neck that houses the vocal cords and is involved in breathing, sound production, and airway protection.

• Unpaired cartilage: Cartilages that occur singly in the larynx such as thyroid, cricoid, and epiglottis.

• Paired cartilage: Cartilages that occur in pairs, including arytenoid, corniculate, and cuneiform.

• Epiglottis: A leaf-shaped unpaired cartilage that covers the glottis during swallowing, preventing aspiration.

• Arytenoid cartilage: Paired cartilages involved in vocal cord movement and phonation.

Lead Question – 2014
Unpaired laryngeal cartilage ?
a) Arytenoid
b) Corniculate
c) Cuneiform
d) Epiglottis

Explanation:
The larynx consists of three unpaired (thyroid, cricoid, epiglottis) and three paired cartilages (arytenoid, corniculate, cuneiform). The epiglottis is a leaf-shaped unpaired cartilage that prevents food from entering the trachea during swallowing. It plays a crucial role in protecting the airway and facilitating speech. Hence, the correct answer is epiglottis (d).

1) Which cartilage forms a complete ring in the larynx?
a) Thyroid
b) Cricoid
c) Arytenoid
d) Corniculate
Explanation: The cricoid cartilage forms a complete ring around the larynx and is the only cartilage with such structure. It provides structural support and connects the larynx to the trachea. The correct answer is cricoid (b).

2) The vocal cords are attached posteriorly to which cartilage?
a) Thyroid
b) Cricoid
c) Arytenoid
d) Epiglottis
Explanation: The vocal cords are attached posteriorly to the arytenoid cartilages and anteriorly to the thyroid cartilage. Arytenoids control tension and position of vocal cords for phonation. The correct answer is arytenoid (c).

3) Which nerve supplies the cricothyroid muscle?
a) Recurrent laryngeal nerve
b) External branch of superior laryngeal nerve
c) Glossopharyngeal nerve
d) Internal laryngeal nerve
Explanation: The cricothyroid muscle is supplied by the external branch of the superior laryngeal nerve. It tenses the vocal cords and modulates pitch. The correct answer is external branch of superior laryngeal nerve (b).

4) A patient with hoarseness after thyroid surgery has likely injured which nerve?
a) Recurrent laryngeal
b) Phrenic
c) Glossopharyngeal
d) Accessory
Explanation: The recurrent laryngeal nerve innervates most intrinsic laryngeal muscles responsible for voice production. Injury during thyroid surgery leads to hoarseness or voice loss. The correct answer is recurrent laryngeal nerve (a).

5) Which muscle abducts the vocal cords?
a) Lateral cricoarytenoid
b) Posterior cricoarytenoid
c) Thyroarytenoid
d) Cricothyroid
Explanation: The posterior cricoarytenoid is the only abductor of the vocal cords, opening the rima glottidis during inspiration. Paralysis causes airway obstruction. The correct answer is posterior cricoarytenoid (b).

6) A child presents with high-pitched breathing after choking. The likely site of obstruction is?
a) Trachea
b) Larynx
c) Nasopharynx
d) Bronchi
Explanation: Stridor, a high-pitched sound, indicates laryngeal obstruction. The larynx’s narrow lumen in children predisposes them to airway compromise. The correct answer is larynx (b).

7) Which cartilage provides attachment for the vocal cords anteriorly?
a) Thyroid
b) Cricoid
c) Arytenoid
d) Epiglottis
Explanation: The anterior ends of the vocal cords attach to the thyroid cartilage at the laryngeal prominence. It provides anchoring for sound modulation. The correct answer is thyroid (a).

8) The laryngeal inlet is guarded by which structure during swallowing?
a) Epiglottis
b) Aryepiglottic fold
c) Vocal cords
d) Cricoid cartilage
Explanation: During swallowing, the epiglottis folds down to cover the laryngeal inlet, preventing food from entering the trachea. The correct answer is epiglottis (a).

9) Which of the following is a paired laryngeal cartilage?
a) Epiglottis
b) Thyroid
c) Corniculate
d) Cricoid
Explanation: The corniculate cartilages are small paired nodules situated on the apices of arytenoid cartilages, assisting in voice production and airway control. The correct answer is corniculate (c).

10) During intubation, which cartilage is felt as the "Adam’s apple"?
a) Cricoid
b) Thyroid
c) Epiglottis
d) Arytenoid
Explanation: The thyroid cartilage projects anteriorly to form the Adam’s apple, most prominent in males. It protects the vocal cords and serves as an important landmark for cricothyrotomy. The correct answer is thyroid (b).

Topic: Vertebral Column; Subtopic: Cervical Vertebrae and Spinous Processes

Keyword Definitions:

• Spinous Process: The posterior bony projection from a vertebra where muscles and ligaments attach.

• Cervical Vertebrae: The seven vertebrae of the neck (C1–C7).

• Vertebra Prominens: The seventh cervical vertebra with a long non-bifid spinous process palpable at the base of the neck.

• Atlas (C1): The first cervical vertebra, supporting the skull.

• Axis (C2): The second cervical vertebra, having the odontoid process (dens).

Lead Question – 2014

Longest spinous process is seen in?

a) C2

b) C4

c) C5

d) C7

Explanation:

The seventh cervical vertebra (C7), also called the vertebra prominens, has the longest spinous process in the cervical region. It is easily palpable at the back of the neck, serving as a landmark for counting vertebrae. Its spine is thick, prominent, and non-bifid, differentiating it from upper cervical spines.

1. Vertebra prominens refers to which vertebra?

a) C1

b) C3

c) C7

d) T1

2. The spinous process of C7 is typically:

a) Bifid

b) Long and non-bifid

c) Absent

d) Fused with T1

3. The transverse foramina of C7 usually transmit:

a) Vertebral artery

b) Vertebral vein only

c) Both artery and vein

d) Sympathetic trunk

4. The most prominent spine palpable in the back of neck when head is flexed belongs to:

a) C6

b) C7

c) T1

d) C5

5. Which cervical vertebra contains the dens (odontoid process)?

a) Atlas

b) Axis

c) C3

d) C7

6. A 30-year-old man with neck trauma shows fracture at vertebra prominens. Which spinal level is affected?

a) C2

b) C6

c) C7

d) T1

7. Which vertebra has the longest spinous process in the thoracic region?

a) T1

b) T5

c) T7

d) T12

8. A surgeon palpates a prominent spine at the base of the neck before incision. This corresponds to:

a) C6

b) C7

c) T1

d) T2

9. Which cervical vertebra has the smallest body and large vertebral foramen?

a) C1

b) C2

c) C3

d) C4

10. A fracture at vertebra prominens can endanger which nearby structure?

a) Brachial plexus

b) Vertebral artery

c) Sympathetic chain

d) Phrenic nerve

11. A patient reports pain at the base of the neck and X-ray shows fracture at vertebra with longest spinous process. Identify the vertebra.

a) C2

b) C5

c) C7

d) T1

Explanation:

The C7 vertebra, or vertebra prominens, is distinct for its long, palpable, non-bifid spinous process. It serves as a key anatomical landmark for locating cervical and thoracic vertebrae. Clinically, it aids in surface anatomy and surgical localization. Therefore, the correct answer is C7.

Chapter: Thorax & Mediastinum; Topic: Sternum & Xiphoid Process; Subtopic: Ossification and Fusion of Xiphoid

Keyword Definitions:

• Xiphoid process: Small inferior cartilaginous/ossified part of the sternum, variable in shape and fusion time.

• Sternum: Midline anterior thoracic bone formed by manubrium, body, and xiphoid process.

• Ossification: Process of cartilage turning into bone during growth and maturation.

• Fusion: The bony union of xiphoid with sternal body, completes skeletal continuity.

• Epigastrium: Region overlying xiphoid; clinical landmark for subxiphoid procedures.

Lead Question - 2014

Xiphoid fuses with sternum by what age ?

a) 30 years
b) 35 years
c) 40 years
d) 45 years

Explanation: The xiphoid process usually ossifies and fuses with the sternal body in middle adulthood; most commonly fusion is complete by around forty years of age. Clinically this is relevant for subxiphoid landmarks and variations; correct answer: c) 40 years.

Guessed Questions for NEET PG (1–10)

1) The xiphoid process is derived from which embryologic tissue?
a) Neural crest
b) Paraxial mesoderm (somites)
c) Lateral plate mesoderm (somatic layer)
d) Endoderm

Explanation: The sternum, including the xiphoid, arises from paired sternal bars derived from the somatic (lateral plate) mesoderm that fuse in the midline during embryogenesis. This explains congenital sternal defects. Correct answer: c) Lateral plate mesoderm (somatic layer).

2) Which structure lies immediately posterior to the xiphoid process in the epigastrium?
a) Right lobe of liver
b) Left lobe of liver
c) Stomach
d) Transverse colon

Explanation: The xiphoid process overlies the superior surface of the left lobe of the liver and the epigastric region; care is required for subxiphoid approaches. In trauma, xiphoid fractures risk liver injury. Correct answer: b) Left lobe of liver.

3) Clinical: A patient has a sharp midline inferior sternal pain after CPR with lower sternal tenderness. Likely injury is to the:
a) Manubrium
b) Sternal body
c) Xiphoid process
d) Costal cartilage

Explanation: Forceful chest compressions can fracture or displace the xiphoid process, causing localized inferior sternal pain and tenderness; this may also injure underlying liver. Clinical suspicion after CPR should include xiphoid injury. Correct answer: c) Xiphoid process.

4) Which of the following muscles attaches to the xiphoid process?
a) Rectus abdominis
b) Transversus thoracis
c) Diaphragm
d) All of the above