Lymphatic System

Chapter: Head and Neck Anatomy; Topic: Lymphatic Drainage of Nose; Subtopic: Anterior and Posterior Nasal Lymphatics

Keyword Definitions:

• Lymphatic drainage: Pathway by which lymph fluid from tissues drains into lymph nodes for immune filtration.

• Submandibular lymph nodes: Nodes located beneath the mandible, draining the anterior nasal cavity, cheek, and lips.

• Pretracheal nodes: Small lymph nodes in front of the trachea, draining thyroid and laryngeal regions.

• Superficial cervical nodes: Nodes along the external jugular vein, receiving lymph from the scalp and face.

Lead Question (2014):
Anterior lymphatics from the nose drain into?
a) Pretracheal nodes
b) Submandibular nodes
c) Sublingual nodes
d) Superficial cervical nodes

Explanation:
The anterior lymphatics of the nose, particularly from the anterior nasal cavity and vestibule, drain into the submandibular lymph nodes. Posterior nasal regions drain into retropharyngeal and upper deep cervical nodes. Understanding these pathways is important in diagnosing nasal and facial infections. Answer: Submandibular nodes. These nodes play a vital role in filtering lymph from anterior facial structures.

1) Posterior nasal cavity lymphatics primarily drain into:
a) Submandibular nodes
b) Retropharyngeal nodes
c) Pretracheal nodes
d) Submental nodes

Explanation:
Lymph from the posterior nasal cavity drains into retropharyngeal nodes, located behind the pharynx. These nodes later communicate with upper deep cervical nodes. Infections in posterior nasal structures, such as adenoids or nasopharyngeal carcinoma, often spread here first. Answer: Retropharyngeal nodes. Their deep location makes clinical detection difficult unless significantly enlarged.

2) Which lymph nodes drain the tip of the nose?
a) Submandibular nodes
b) Submental nodes
c) Superficial parotid nodes
d) Deep cervical nodes

Explanation:
The tip of the nose and adjacent alae drain primarily into the submandibular nodes. However, some lymph from the midline of the lower lip and chin may reach submental nodes. Answer: Submandibular nodes. This pattern is clinically important because infections at the nasal vestibule or furuncles can cause tender swelling beneath the jawline.

3) A patient with a nasal vestibular abscess will most likely have tenderness over which lymph nodes?
a) Pretracheal
b) Submandibular
c) Deep cervical
d) Retropharyngeal

Explanation:
A nasal vestibular abscess drains anteriorly into the submandibular lymph nodes, leading to tenderness and swelling under the mandible. These nodes filter lymph from the anterior nose, cheek, and upper lip. Answer: Submandibular nodes. Clinically, enlarged submandibular nodes help localize infections to anterior facial regions or vestibular furuncles.

4) Posterior nasal lymphatics ultimately reach which group of deep cervical nodes?
a) Jugulodigastric
b) Jugulo-omohyoid
c) Supraclavicular
d) Pretracheal

Explanation:
Posterior nasal lymphatics drain via retropharyngeal nodes into the jugulodigastric nodes, one of the key deep cervical lymph nodes. These receive lymph from nasopharynx, tonsils, and posterior scalp. Answer: Jugulodigastric nodes. Their enlargement may indicate infections like tonsillitis or malignancy in posterior nasal or pharyngeal regions.

5) Which lymph nodes receive drainage from both the nose and upper lip?
a) Submandibular
b) Submental
c) Retropharyngeal
d) Superficial cervical

Explanation:
Both the nose and upper lip drain into the submandibular lymph nodes. This overlap explains why infections around the mouth and nose can spread rapidly, even causing cavernous sinus thrombosis in severe cases. Answer: Submandibular nodes. These nodes are palpable below the jawline and are clinically relevant in facial cellulitis evaluation.

6) A carcinoma in the nasal septum anteriorly will first spread to:
a) Retropharyngeal nodes
b) Submandibular nodes
c) Deep cervical nodes
d) Prelaryngeal nodes

Explanation:
Cancer in the anterior nasal septum first metastasizes to submandibular lymph nodes. The anterior lymphatic drainage pattern directs lymph flow toward these superficial nodes before reaching deeper cervical nodes. Answer: Submandibular nodes. Palpation of submandibular nodes is vital in head and neck oncology to detect early regional spread.

7) The posterior nasal cavity and nasopharynx share lymphatic drainage with which structure?
a) Palatine tonsil
b) Parotid gland
c) Tongue tip
d) Lower lip

Explanation:
Both the posterior nasal cavity and palatine tonsil drain into retropharyngeal and upper deep cervical (jugulodigastric) nodes. This shared drainage explains why nasopharyngeal carcinoma may spread to tonsillar lymphatic pathways. Answer: Palatine tonsil. Awareness of these connections helps clinicians assess metastasis patterns in head and neck malignancies.

8) Inflammation over the bridge of the nose drains to which lymph node group?
a) Preauricular
b) Submandibular
c) Retropharyngeal
d) Occipital

Explanation:
The bridge of the nose drains into submandibular lymph nodes, while lateral aspects may communicate with preauricular nodes. In infections like cellulitis or furuncles, submandibular tenderness is a key sign. Answer: Submandibular nodes. Prompt management is crucial as facial veins lack valves, increasing risk of cavernous sinus spread.

9) Deep cervical lymph nodes receive indirect drainage from nasal structures via which group?
a) Retropharyngeal
b) Pretracheal
c) Submental
d) Submandibular

Explanation:
The deep cervical lymph nodes collect lymph from the nose indirectly through retropharyngeal and submandibular nodes. These act as intermediary stations before lymph enters the jugular trunk. Answer: Retropharyngeal nodes. The sequence reflects the structured lymphatic hierarchy in the head and neck drainage network.

10) A patient with posterior nasal carcinoma has enlarged deep cervical nodes. The spread occurred through which intermediate group?
a) Submandibular
b) Retropharyngeal
c) Pretracheal
d) Parotid

Explanation:
Posterior nasal or nasopharyngeal carcinomas first spread to the retropharyngeal nodes, then to the deep cervical (jugulodigastric) group. Answer: Retropharyngeal nodes. These nodes are often the first indicator of malignancy in this region. Their involvement provides essential clues in imaging and surgical planning for head and neck cancers.

Topic: Lymphatic System; Subtopic: Termination of Thoracic Duct

Keyword Definitions:

• Thoracic duct: Largest lymphatic channel, draining lymph from most of the body except right upper quadrant.

• Venous angle: Junction of internal jugular vein and subclavian vein.

• Subclavian vein: Major vein draining blood from the upper limb.

• Internal jugular vein: Vein draining blood from brain, face, and neck.

• Brachiocephalic vein: Large vein formed by union of subclavian and internal jugular veins.

Lead Question - 2014
Thoracic duct opens into ?
a) Subclavian vein
b) Internal jugular vein
c) Right brachiocephalic vein
d) Left brachiocephalic vein

Explanation: The thoracic duct terminates at the left venous angle, i.e., the junction of the left subclavian and left internal jugular veins. This anatomical site is critical in surgeries of the neck and mediastinum. Correct answer: a) Subclavian vein (at its junction with internal jugular vein).

Guessed Questions for NEET PG:

1) Which side of the venous angle receives thoracic duct?
a) Right
b) Left
c) Both sides
d) Variable

Explanation: The thoracic duct consistently terminates at the left venous angle, formed by left internal jugular and left subclavian veins. This is a fixed anatomical feature with great surgical relevance. Correct answer: b) Left.

2) Right lymphatic duct opens into?
a) Left venous angle
b) Right venous angle
c) Superior vena cava
d) Azygos vein

Explanation: The right lymphatic duct drains lymph from right upper limb, right thorax, and right side of head and neck. It opens into the right venous angle, i.e., junction of right internal jugular and subclavian veins. Correct answer: b) Right venous angle.

3) Length of thoracic duct is?
a) 10 cm
b) 20 cm
c) 40 cm
d) 60 cm

Explanation: The thoracic duct measures approximately 40 cm in adults. It extends from cisterna chyli at L1-L2 vertebrae to the left venous angle in the root of the neck. Correct answer: c) 40 cm.

4) Thoracic duct crosses from right to left at the level of?
a) T2
b) T4
c) T6
d) T8

Explanation: The thoracic duct ascends on the right side of vertebral column and crosses to the left side at the level of T4-T6 vertebrae, continuing upward to terminate in the left venous angle. Correct answer: b) T4.

5) A 45-year-old man develops chylothorax after oesophagectomy. Which structure is injured?
a) Azygos vein
b) Thoracic duct
c) Hemiazygos vein
d) Vagus nerve

Explanation: Chylothorax results from thoracic duct injury during mediastinal or esophageal surgery. Milky fluid rich in triglycerides accumulates in the pleural cavity, requiring drainage. Correct answer: b) Thoracic duct.

6) Cisterna chyli is located at?
a) T10
b) T12
c) L1-L2
d) S1

Explanation: The cisterna chyli is located anterior to the bodies of L1 and L2 vertebrae. It collects lymph from lumbar and intestinal trunks and continues as thoracic duct. Correct answer: c) L1-L2.

7) Thoracic duct drains all except?
a) Right lower limb
b) Left upper limb
c) Right thorax
d) Left thorax

Explanation: The thoracic duct drains both lower limbs, abdomen, left thorax, left upper limb, and left head and neck. The right thorax, right upper limb, and right head and neck are drained by the right lymphatic duct. Correct answer: c) Right thorax.

8) In a left neck dissection, accidental thoracic duct injury causes leakage of?
a) Blood
b) Serous fluid
c) Chyle
d) Bile

Explanation: Injury to thoracic duct causes leakage of chyle, a milky lymph rich in fats. Chylous fistula is a known complication in neck surgeries, particularly near left venous angle. Correct answer: c) Chyle.

9) In lymphoma, obstruction of thoracic duct may cause?
a) Pleural effusion
b) Ascites
c) Chylous ascites
d) Pericardial effusion

Explanation: Thoracic duct obstruction by lymphoma or tumor can cause chylous ascites, characterized by milky fluid in the peritoneal cavity due to blocked lymphatic flow. Correct answer: c) Chylous ascites.

10) During ligation of thoracic duct, surgeon aims to prevent?
a) Air embolism
b) Chylothorax
c) Pneumothorax
d) Pulmonary embolism

Explanation: Ligation of thoracic duct is done to prevent persistent chylothorax, which results from continuous leakage of chyle into pleural cavity. This is life-threatening due to nutritional loss. Correct answer: b) Chylothorax.

Subtopic: Thoracic Duct Formation

Keyword Definitions:

• Thoracic duct: The largest lymphatic vessel in the human body draining lymph from most areas.

• Cisterna chyli: Dilated sac at the lower end of thoracic duct collecting lymph from abdomen.

• Subclavian vein: Vein that drains blood from upper limb into brachiocephalic vein.

• Jugular vein: Vein draining blood from head and neck.

• Brachiocephalic vein: Large vein formed by subclavian and internal jugular veins.

Lead Question - 2014
Thoracic duct is formed by?
a) Union of left subclavian and left internal jugular vein.
b) Union of brachiocephalic vein and internal jugular vein
c) Continuation of upper end of cisterna chyli
d) None of the above

Explanation: The thoracic duct originates as the continuation of the cisterna chyli at the level of L1-L2 vertebrae, ascending through the thorax. It drains into the venous system at the junction of the left internal jugular and left subclavian veins. Correct answer: c) Continuation of upper end of cisterna chyli.

Guessed Questions for NEET PG:

1) Length of thoracic duct is approximately?
a) 10 cm
b) 20 cm
c) 40 cm
d) 50 cm

Explanation: The thoracic duct measures about 40 cm in adults. It starts from cisterna chyli in the abdomen and ascends to the venous angle. Its long course makes it prone to injury during surgery. Correct answer: c) 40 cm.

2) Thoracic duct pierces diaphragm through?
a) Aortic hiatus
b) Caval opening
c) Esophageal hiatus
d) None

Explanation: The thoracic duct passes through the diaphragm along with the aorta at the aortic hiatus at the level of T12 vertebra. This is a key anatomical relation during abdominal and thoracic surgeries. Correct answer: a) Aortic hiatus.

3) Which vein receives terminal drainage of thoracic duct?
a) Right subclavian vein
b) Left brachiocephalic vein
c) At junction of left internal jugular and left subclavian vein
d) Superior vena cava

Explanation: The thoracic duct terminates into the venous system at the left venous angle, i.e., the junction of the left subclavian vein and left internal jugular vein. This is a key anatomical landmark. Correct answer: c) Junction of left internal jugular and subclavian vein.

4) Thoracic duct drains all except?
a) Left upper limb
b) Right thorax
c) Left abdomen
d) Left thorax

Explanation: The thoracic duct drains lymph from entire body except the right upper limb, right thorax, right side of head and neck, which are drained by the right lymphatic duct. Correct answer: b) Right thorax.

5) In a neck surgery, thoracic duct injury leads to leakage of?
a) Blood
b) Bile
c) Chyle
d) Lymphocyte-depleted fluid

Explanation: Injury to thoracic duct leads to chylous fistula, with leakage of milky chyle rich in triglycerides. This complication is common during left neck dissections near the venous angle. Correct answer: c) Chyle.

6) Cisterna chyli is located at?
a) T8-T9
b) L1-L2
c) S1-S2
d) T12

Explanation: The cisterna chyli is located anterior to the bodies of L1 and L2 vertebrae, behind the right crus of diaphragm. It acts as the reservoir for intestinal and lumbar lymph trunks. Correct answer: b) L1-L2.

7) In chylothorax, fluid accumulates in?
a) Pleural cavity
b) Peritoneal cavity
c) Pericardial cavity
d) Subarachnoid space

Explanation: Chylothorax occurs when the thoracic duct is injured, leading to leakage of chyle into the pleural cavity. It is a serious surgical complication, requiring drainage and repair. Correct answer: a) Pleural cavity.

8) Right lymphatic duct drains lymph from?
a) Right upper limb
b) Right thorax
c) Right side of head and neck
d) All of the above

Explanation: The right lymphatic duct drains lymph from right upper limb, right thorax, and right side of head and neck. It terminates into the right venous angle. Correct answer: d) All of the above.

9) In case of lymphoma, thoracic duct obstruction may cause?
a) Ascites
b) Chylothorax
c) Chylous ascites
d) Edema

Explanation: Thoracic duct obstruction due to malignancy such as lymphoma may cause chylous ascites, characterized by milky fluid in peritoneum. This is a clinical indicator of lymphatic obstruction. Correct answer: c) Chylous ascites.

10) During oesophageal carcinoma surgery, thoracic duct is at risk at level of?
a) T2
b) T4
c) T8
d) T12

Explanation: Thoracic duct runs posterior to oesophagus in thorax, closely related at T4 to T8 levels. Surgical manipulation in esophagectomy carries risk of injury. Correct answer: c) T8.

Chapter: Anatomy

Topic: Pelvis

Subtopic: Lymphatic Drainage of Female Reproductive Organs

Keyword Definitions:

• Para-aortic lymph nodes: Lymph nodes along the abdominal aorta, draining ovaries, uterine tubes, and upper uterus.

• External iliac lymph nodes: Nodes along external iliac vessels, draining upper bladder, cervix, and upper vagina.

• Superior inguinal lymph nodes: Located in femoral triangle, draining lower vulva, lower vagina, and superficial structures of lower limb.

• Deep inguinal lymph nodes: Beneath fascia lata, draining glans penis/clitoris, deep lower limb structures.

• Pelvic lymph nodes: Network including obturator, internal iliac, external iliac, and sacral nodes.

• Clinical relevance: Knowledge of lymphatic drainage is vital for staging cervical and vaginal cancers and planning surgery or radiotherapy.

Lead Question - 2013

Which lymph nodes drain upper vagina & cervix?

a) Para aortic
b) External iliac
c) Superior inguinal
d) Deep inguinal

Explanation: The upper vagina and cervix primarily drain into the external iliac lymph nodes, with some drainage to internal iliac and obturator nodes. Para-aortic nodes mainly drain ovaries and uterine tubes. Correct answer is b) External iliac.

Guessed Question 2

Lower vagina primarily drains into?

a) External iliac nodes
b) Internal iliac nodes
c) Superior inguinal nodes
d) Para-aortic nodes

Explanation: The lower vagina and vulva drain primarily into superficial and superior inguinal lymph nodes, providing a pathway for potential metastasis. Correct answer is c) Superior inguinal nodes.

Guessed Question 3

Ovaries drain mainly to which lymph nodes?

a) External iliac
b) Internal iliac
c) Para-aortic
d) Inguinal

Explanation: Ovarian lymphatics follow the ovarian vessels to the para-aortic (lumbar) lymph nodes near the renal vessels. Correct answer is c) Para-aortic.

Guessed Question 4

Cervical cancer commonly metastasizes to which nodes first?

a) Para-aortic
b) External iliac
c) Superior inguinal
d) Sacral

Explanation: Early cervical cancer spreads to the external iliac, internal iliac, and obturator nodes. Para-aortic and sacral involvement occurs later. Correct answer is b) External iliac.

Guessed Question 5

Which lymph nodes lie along obturator vessels?

a) Obturator nodes
b) External iliac nodes
c) Superior inguinal nodes
d) Para-aortic nodes

Explanation: Obturator lymph nodes are situated along the obturator vessels, draining the pelvic floor, bladder, cervix, and upper vagina. Correct answer is a) Obturator nodes.

Guessed Question 6

Deep inguinal lymph nodes receive drainage from?

a) Lower limb
b) Upper vagina
c) Cervix
d) Para-aortic nodes

Explanation: Deep inguinal nodes lie beneath fascia lata and receive lymph from the lower limb, glans penis/clitoris, and deep structures of the lower pelvis. Correct answer is a) Lower limb.

Guessed Question 7

Which nodes are involved in vulvar carcinoma?

a) Para-aortic
b) Superior inguinal
c) External iliac
d) Obturator

Explanation: Vulvar carcinoma primarily drains to superficial and superior inguinal lymph nodes, which are first sites of metastasis. Correct answer is b) Superior inguinal.

Guessed Question 8

Internal iliac lymph nodes drain?

a) Upper bladder, cervix, uterus
b) Lower limb
c) Ovaries
d) Lower vagina only

Explanation: Internal iliac nodes drain the cervix, upper vagina, bladder, and uterus, forming an important part of pelvic lymphatic network. Correct answer is a) Upper bladder, cervix, uterus.

Guessed Question 9

Para-aortic nodes are clinically important in?

a) Staging ovarian cancer
b) Breast cancer
c) Colon cancer
d) Thyroid cancer

Explanation: Para-aortic lymph nodes receive lymph from ovaries, uterine tubes, and upper uterus, serving as a key site in staging ovarian and some uterine cancers. Correct answer is a) Staging ovarian cancer.

Guessed Question 10

Which pelvic node group is commonly biopsied in cervical cancer?

a) External iliac
b) Para-aortic
c) Superior inguinal
d) Deep inguinal

Explanation: External iliac nodes are commonly biopsied or sampled during pelvic lymphadenectomy in cervical cancer due to their early involvement. Correct answer is a) External iliac.

Guessed Question 11

Obturator nodes are located in relation to?

a) Obturator vessels
b) External iliac vessels
c) Internal thoracic artery
d) Para-aortic region

Explanation: Obturator lymph nodes lie along obturator vessels in the obturator fossa and are part of the primary drainage pathway of the cervix and upper vagina. Correct answer is a) Obturator vessels.

Keyword Definitions

• Ossification center – Specific area where bone formation begins.

• Primary ossification center – Appears before birth, usually in diaphysis of long bones.

• Secondary ossification center – Appears after birth, mostly at epiphyses.

• Epiphysis – End part of long bone, separated by growth plate.

• Growth plate (physis) – Cartilaginous zone responsible for bone lengthening.

• Femur – Longest bone in the body, crucial for weight bearing.

• Lower end of femur – Includes medial and lateral condyles, important for knee joint stability.

• Clinical correlation – Injuries near growth plate may cause deformity in children.

• Fusion of ossification centers – Indicates skeletal maturity, useful in forensic medicine.

• Pathology – Delay in ossification may suggest rickets or endocrinological disorders.

Chapter: Anatomy / Lower Limb

Topic: Ossification of Femur

Subtopic: Lower End of Femur

Lead Question – 2013

Lower end of femur is ossified from how many ossification centers?

a) 1

b) 2

c) 3

d) 4

Explanation: The lower end of femur is ossified from a single secondary ossification center, which appears at birth and is the largest epiphyseal center in the body. It helps determine gestational age in newborn radiographs. Correct answer: 1.

Guessed Questions for NEET PG

1) The first secondary ossification center to appear in the body is?

a) Head of femur

b) Lower end of femur

c) Upper end of tibia

d) Calcaneus

Explanation: The lower end of femur and upper end of tibia are the earliest secondary ossification centers, both appearing at birth. These are crucial in neonatal skeletal age estimation. Correct answer: Lower end of femur.

2) Which ossification center is used to determine fetal maturity in X-rays?

a) Upper end of humerus

b) Lower end of femur

c) Upper end of fibula

d) Clavicle

Explanation: The presence of the ossification center in the lower end of femur indicates intrauterine maturity after 36 weeks of gestation. Correct answer: Lower end of femur.

3) The lower end of femur fuses with shaft at what age?

a) 12 years

b) 16 years

c) 20 years

d) 25 years

Explanation: Fusion of the lower end of femur with diaphysis occurs around 20 years of age, making it a reliable marker for skeletal maturity in forensic medicine. Correct answer: 20 years.

4) Which epiphysis is the largest secondary ossification center?

a) Proximal humerus

b) Distal femur

c) Proximal tibia

d) Iliac crest

Explanation: The distal femoral epiphysis is the largest secondary ossification center, covering the condylar region. It plays a crucial role in knee growth. Correct answer: Distal femur.

5) In rickets, which ossification center shows delayed appearance?

a) Lower end of femur

b) Upper end of tibia

c) Distal radius

d) All of the above

Explanation: Rickets causes generalized delay in appearance of secondary ossification centers, including lower femur, tibia, and wrist bones. Correct answer: All of the above.

6) The ossification center at the head of femur appears at?

a) Birth

b) 1 year

c) 3 months

d) 6 years

Explanation: The head of femur ossification center appears at around 1 year of age, useful in pediatric radiology. Correct answer: 1 year.

7) Which bone has both membranous and cartilaginous ossification?

a) Femur

b) Clavicle

c) Tibia

d) Radius

Explanation: The clavicle develops from both intramembranous and endochondral ossification, unlike femur which is purely cartilaginous in origin. Correct answer: Clavicle.

8) A neonate with no ossification center at lower femur is likely?

a) Term baby

b) Preterm baby

c) Post-term baby

d) Growth restricted baby only

Explanation: Absence of ossification center at the lower femur suggests prematurity (

9) Which of the following is true about epiphyseal injuries in femur?

a) Common in adults

b) Affect growth potential

c) Do not cause deformity

d) Heals without complications

Explanation: Epiphyseal injuries in the distal femur can affect growth and cause angular deformities due to damage of growth plate. Correct answer: Affect growth potential.

10) The nutrient artery of femur enters from?

a) Upper end

b) Middle third posterior surface

c) Lower end

d) Anterior surface

Explanation: The nutrient artery enters the shaft of femur from the middle third on its posterior surface, directed towards the knee ("to the elbow I go, from the knee I flee"). Correct answer: Middle third posterior surface.

Keyword Definitions

• Lymph nodes – Small immune structures filtering lymphatic fluid.

• Superficial inguinal lymph nodes – Drain superficial structures of lower limb, external genitalia, and lower abdominal wall.

• Deep inguinal nodes – Located beneath fascia lata, drain deep lymphatics of lower limb.

• External iliac nodes – Drain lymph from pelvic organs and deep inguinal nodes.

• Internal iliac nodes – Drain pelvic viscera, perineum, and gluteal region.

• Great toe lymphatics – Superficial drainage follows great saphenous vein to superficial inguinal nodes.

• Popliteal lymph nodes – Located behind knee, drain deep tissues of leg.

• Clinical correlation – Swelling in groin may indicate infection or malignancy in drainage territory.

• Saphenous vein – Long superficial vein of leg, associated with superficial lymphatics.

• Sentinel lymph node – First node to receive lymph from cancer site, important in oncology.

Chapter: Anatomy / Lower Limb

Topic: Lymphatic Drainage

Subtopic: Drainage of Foot and Great Toe

Lead Question – 2013

Skin and fascia of great toe drains into?

a) Superficial inguinal lymph nodes

b) External iliac nodes

c) Internal iliac nodes

d) Deep inguinal nodes

Explanation: The superficial lymphatics of the great toe accompany the great saphenous vein and drain primarily into the superficial inguinal lymph nodes. Deep lymphatics, however, drain into deep inguinal and external iliac nodes. Correct answer: Superficial inguinal lymph nodes.

Guessed Questions for NEET PG

1) Lymph from the glans penis drains into?

a) Superficial inguinal nodes

b) Deep inguinal nodes

c) External iliac nodes

d) Internal iliac nodes

Explanation: Lymph from the glans penis and clitoris drains into deep inguinal lymph nodes (node of Cloquet). This clinical correlation is important in genitourinary cancers. Correct answer: Deep inguinal nodes.

2) Infection at the lateral side of the foot drains initially into?

a) Popliteal nodes

b) Superficial inguinal nodes

c) Deep inguinal nodes

d) External iliac nodes

Explanation: Lymphatics from the lateral foot follow the small saphenous vein and drain into popliteal lymph nodes before reaching deeper nodes. Correct answer: Popliteal nodes.

3) Which lymph nodes are involved in carcinoma of the anal canal below pectinate line?

a) Internal iliac nodes

b) External iliac nodes

c) Superficial inguinal nodes

d) Para-aortic nodes

Explanation: The anal canal below the pectinate line drains into superficial inguinal nodes, explaining why inguinal swelling may be an early sign of malignancy. Correct answer: Superficial inguinal nodes.

4) The node of Cloquet is located in?

a) Femoral ring

b) Adductor canal

c) Inguinal ligament

d) Popliteal fossa

Explanation: The node of Cloquet is the highest deep inguinal lymph node, located in the femoral canal, and communicates with external iliac nodes. Correct answer: Femoral ring.

5) Which lymph nodes drain the uterus near the round ligament?

a) Internal iliac nodes

b) Para-aortic nodes

c) Superficial inguinal nodes

d) External iliac nodes

Explanation: Lymphatics from the uterus near the round ligament follow the ligament to reach the superficial inguinal nodes. Correct answer: Superficial inguinal nodes.

6) Which is the sentinel node in carcinoma of the cervix?

a) Internal iliac nodes

b) External iliac nodes

c) Superficial inguinal nodes

d) Para-aortic nodes

Explanation: The primary lymphatic drainage of cervix is to the internal iliac and sacral nodes, making them sentinel nodes for carcinoma cervix. Correct answer: Internal iliac nodes.

7) Enlargement of which nodes may indicate infection in the great toe?

a) Deep inguinal nodes

b) Superficial inguinal nodes

c) External iliac nodes

d) Para-aortic nodes

Explanation: Infection of great toe skin or fascia drains to superficial inguinal nodes, which enlarge clinically. Correct answer: Superficial inguinal nodes.

8) Popliteal lymph nodes drain all except?

a) Lateral side of sole

b) Heel region

c) Lateral border of foot

d) Medial side of great toe

Explanation: The medial side of great toe drains into superficial inguinal nodes, not popliteal nodes. Correct answer: Medial side of great toe.

9) Lymphatic obstruction in the femoral canal primarily affects?

a) Deep inguinal nodes

b) Superficial inguinal nodes

c) Popliteal nodes

d) Internal iliac nodes

Explanation: The femoral canal contains the node of Cloquet, which is part of deep inguinal lymphatic drainage. Obstruction here causes lower limb lymphedema. Correct answer: Deep inguinal nodes.

10) Which lymph nodes are first affected in carcinoma of the testis?

a) Superficial inguinal nodes

b) Deep inguinal nodes

c) Para-aortic nodes

d) External iliac nodes

Explanation: Testicular lymphatics follow gonadal vessels and drain into para-aortic (lumbar) nodes, not inguinal nodes. Correct answer: Para-aortic nodes.

Keyword Definitions

• Axillary lymph nodes – Group of nodes in axilla draining upper limb, breast, thoracic wall.

• Anterior (pectoral) group – Along lateral thoracic vessels, drains anterior thoracic wall & breast.

• Posterior (subscapular) group – Along subscapular vessels, drains posterior thoracic wall & scapular region.

• Lateral group – Along axillary vein, drains upper limb.

• Central group – In fat of axilla, receives from anterior, posterior, lateral groups.

• Apical group – At apex of axilla, drains all other axillary nodes, terminal group.

• Axillary vein – Major vessel of axilla, closely related to lateral nodes.

• Sentinel lymph node – First node receiving lymph from primary tumor site.

• Breast carcinoma – Common malignancy spreading to axillary nodes.

• Radical mastectomy – Surgical removal of breast with axillary lymph node dissection.

• Lymphedema – Swelling due to lymphatic obstruction, common complication after axillary dissection.

Chapter: Anatomy / Upper Limb

Topic: Axilla

Subtopic: Axillary Lymph Nodes

Lead Question – 2013

All are true regarding axillary lymph nodes except?

a) Posterior group lies along subscapular vessels

b) Lateral group lies along lateral thoracic vessels

c) Apical group lies along axillary vessels

d) Apical group is terminal lymph nodes

Explanation: The lateral group lies along the axillary vein, not the lateral thoracic vessels. The anterior (pectoral) group lies along the lateral thoracic vessels. Correct answer: (b). Clinical: Understanding axillary lymph node anatomy is vital in breast cancer surgery for staging and prevention of lymphedema.

Guessed Questions for NEET PG

1) Which axillary lymph node group directly drains the breast?

a) Posterior

b) Anterior

c) Lateral

d) Central

Explanation: The anterior (pectoral) group, located along the lateral thoracic vessels, directly drains most of the breast. Correct answer: Anterior group. Clinical: In breast cancer, these are the first nodes involved and often targeted in sentinel lymph node biopsy.

2) Central lymph nodes receive lymph from:

a) Only anterior group

b) Anterior, posterior, lateral groups

c) Only posterior group

d) Apical group

Explanation: Central lymph nodes in the axillary fat collect lymph from anterior, posterior, and lateral groups. Correct answer: Anterior, posterior, lateral groups. Clinical: Their involvement suggests spread of malignancy beyond primary drainage pathways.

3) Which group of axillary nodes is considered terminal?

a) Lateral

b) Apical

c) Central

d) Posterior

Explanation: Apical group, at apex of axilla near axillary vein, serves as the terminal collecting group for all axillary lymph nodes. Correct answer: Apical group. Clinical: Spread to these nodes indicates advanced disease, often involving supraclavicular spread.

4) Sentinel lymph node biopsy in breast cancer is done to:

a) Remove all axillary nodes

b) Identify first draining node

c) Treat lymphedema

d) Block venous drainage

Explanation: Sentinel lymph node biopsy helps identify the first lymph node draining a tumor. Correct answer: Identify first draining node. Clinical: If negative, extensive axillary dissection may be avoided, reducing complications like lymphedema.

5) Which axillary group lies along the axillary vein?

a) Lateral

b) Central

c) Posterior

d) Apical

Explanation: The lateral group lies along the axillary vein and drains the majority of the upper limb. Correct answer: Lateral group. Clinical: Infections of hand and arm may cause painful swelling of this group.

6) A 40-year-old woman with carcinoma of upper outer quadrant breast: most likely first lymph node involved?

a) Posterior

b) Anterior

c) Apical

d) Central

Explanation: Carcinoma of upper outer quadrant drains to anterior group, which communicates with central nodes. Correct answer: Anterior group. Clinical: Upper outer quadrant tumors metastasize early due to rich lymphatic drainage.

7) Which axillary node group is closely related to subscapular vessels?

a) Anterior

b) Posterior

c) Lateral

d) Apical

Explanation: The posterior group, also called subscapular nodes, lies along subscapular vessels. Correct answer: Posterior group. Clinical: They receive lymph from posterior thoracic wall and scapular region.

8) Lymphedema of upper limb after mastectomy is due to removal of:

a) Posterior nodes

b) Apical nodes

c) Axillary nodes

d) Central nodes

Explanation: Removal of axillary nodes blocks lymphatic drainage of upper limb, causing lymphedema. Correct answer: Axillary nodes. Clinical: Patients are advised physiotherapy and arm care after surgery to reduce risk.

9) Which statement about apical lymph nodes is false?

a) They are terminal axillary nodes

b) They lie along axillary vein at apex

c) They receive lymph directly from breast

d) They drain into subclavian lymph trunk

Explanation: Apical nodes do not directly drain the breast; anterior group does. Correct answer: (c). Clinical: Apical nodes represent final common pathway before lymph enters subclavian trunk.

10) Which group of axillary nodes communicates with supraclavicular nodes?

a) Central

b) Apical

c) Lateral

d) Posterior

Explanation: Apical group communicates with supraclavicular nodes via subclavian lymph trunk. Correct answer: Apical group. Clinical: Supraclavicular involvement in breast cancer indicates advanced metastatic spread.

Keyword Definitions

• Lymph node – Small encapsulated lymphoid organ along lymphatic vessels; filters lymph and initiates immune responses.

• Cortex – Outer portion of lymph node containing lymphoid follicles; mainly B-cell areas.

• Medulla – Inner portion of lymph node; contains medullary cords and sinuses; plasma cells reside here.

• Follicles – Spherical aggregates of lymphocytes within cortex; primary follicles are inactive, secondary follicles contain germinal centers.

• Germinal center – Site of B-cell proliferation, differentiation, and somatic hypermutation after antigen stimulation.

• Paracortex – Area between cortex and medulla; rich in T-cells surrounding high endothelial venules (HEVs).

• Lymphatic sinuses – Channels within node for lymph flow; subcapsular, trabecular, and medullary sinuses.

• High endothelial venules (HEVs) – Specialized vessels allowing lymphocyte entry into lymph nodes.

• Clinical relevance – Follicular hyperplasia indicates infection or immune activation; neoplasms like follicular lymphoma arise from follicles.

• Embryology – Lymph nodes develop from mesenchymal cells; colonize by lymphocytes in late fetal life.

Chapter: Histology / Immunology

Topic: Lymphoid Organs

Subtopic: Lymph Node Structure

Lead Question – 2013

Follicles are present in which part of lymph nodes?

a) Red pulp

b) White pulp

c) Cortex

d) Medulla

Explanation: Lymphoid follicles are present in the cortex of lymph nodes, forming B-cell rich zones. Primary follicles are inactive, while secondary follicles contain germinal centers after antigen exposure. Correct answer: Cortex. Medulla contains plasma cells, and red/white pulp refer to spleen. Follicular hyperplasia occurs in infections or autoimmune conditions.

Guessed Questions for NEET PG

1) Paracortex of lymph node contains:

a) T-cells

b) B-cells

c) Plasma cells

d) Fibroblasts

Explanation: Paracortex is rich in T-lymphocytes surrounding HEVs. Correct answer: T-cells. Clinical: T-cell deficiency affects cell-mediated immunity and lymph node structure.

2) Medullary cords contain:

a) Plasma cells

b) T-cells

c) B-cells in follicles

d) Red pulp

Explanation: Medullary cords in lymph node medulla contain plasma cells and macrophages. Correct answer: Plasma cells. Clinical: antibody production is concentrated here.

3) Subcapsular sinus is located:

a) Beneath capsule

b) Cortex

c) Medulla

d) Follicles

Explanation: Subcapsular sinus lies just below the lymph node capsule, allowing lymph to flow into trabecular sinuses. Correct answer: Beneath capsule. Clinical: site for metastatic cancer cell entry.

4) Secondary follicles contain:

a) Germinal centers

b) T-cells only

c) Medullary cords

d) Capsule fibroblasts

Explanation: Secondary follicles develop germinal centers after antigen stimulation. Correct answer: Germinal centers. Clinical: hyperactive germinal centers appear in infections and autoimmune disease.

5) High endothelial venules (HEVs) are in:

a) Paracortex

b) Cortex follicles

c) Medullary cords

d) Sinuses

Explanation: HEVs in paracortex allow lymphocyte migration from blood to lymph node. Correct answer: Paracortex. Clinical: impaired HEV function reduces lymphocyte homing.

6) Primary follicles are:

a) Inactive B-cell clusters

b) Germinal centers

c) Medullary cords

d) Paracortex T-cells

Explanation: Primary follicles are small, inactive B-cell clusters in cortex. Correct answer: Inactive B-cell clusters. Clinical: may enlarge in early immune response.

7) Lymph node capsule is composed of:

a) Dense connective tissue

b) B-cell follicles

c) Medullary cords

d) Paracortex

Explanation: Capsule is dense connective tissue providing protection and structure. Correct answer: Dense connective tissue. Clinical: capsule rupture can spread infection or metastasis.

8) Trabeculae of lymph nodes carry:

a) Blood vessels and lymphatics

b) Only sinuses

c) Only follicles

d) Red pulp

Explanation: Trabeculae carry vessels and lymph channels from capsule into interior. Correct answer: Blood vessels and lymphatics. Clinical: obstruction can impair lymph flow.

9) Medullary sinuses drain into:

a) Efferent lymphatics

b) Afferent lymphatics

c) Capsule

d) Paracortex

Explanation: Medullary sinuses drain lymph into efferent lymphatic vessels. Correct answer: Efferent lymphatics. Clinical: blockage leads to lymph node swelling.

10) Follicular lymphoma arises from:

a) B-cell follicles

b) T-cell paracortex

c) Medullary cords

d) Capsule

Explanation: Follicular lymphoma is a B-cell malignancy originating from cortical follicles. Correct answer: B-cell follicles. Clinical: presents as painless lymphadenopathy and may involve multiple lymph nodes.

Keyword Definitions

• Spleen – Lymphoid organ in the left upper abdomen; filters blood, stores blood, and provides immune surveillance.

• White pulp – Lymphoid tissue surrounding central arteries; mainly composed of lymphocytes; site of immune responses.

• Red pulp – Vascular tissue with sinusoids and cords (Billroth’s cords); removes aged red blood cells and pathogens.

• B-cells – Lymphocytes responsible for humoral immunity; produce antibodies; primarily located in white pulp follicles.

• T-cells – Lymphocytes involved in cell-mediated immunity; mainly found in periarteriolar lymphoid sheath (PALS).

• Germinal centers – Sites of B-cell proliferation and differentiation within white pulp follicles.

• Central artery – Artery surrounded by PALS in white pulp.

• Billroth’s cords – Structures in red pulp containing macrophages, lymphocytes, and plasma cells.

• Capsule – Dense connective tissue surrounding spleen; provides protection.

• Clinical relevance – B-cell deficiencies lead to poor humoral response; splenectomy affects antibody production.

Chapter: Histology / Immunology

Topic: Lymphoid Organs

Subtopic: Spleen Cell Distribution

Lead Question – 2013

B-cells are dispersed in which part of spleen?

a) White pulp

b) Red pulp

c) Capsule

d) None

Explanation: B-cells are primarily located in the follicles of white pulp surrounding central arteries. They form germinal centers upon antigen stimulation and produce antibodies. Correct answer: White pulp. Red pulp contains mainly macrophages and plasma cells. Clinical relevance: B-cell deficiencies reduce humoral immunity, increasing susceptibility to infections.

Guessed Questions for NEET PG

1) T-cells are concentrated in:

a) PALS of white pulp

b) Red pulp

c) Capsule

d) Sinusoids

Explanation: T-cells mainly surround central arteries in PALS within white pulp. Correct answer: PALS of white pulp. Clinical: T-cell defects impair cell-mediated immunity, predisposing to viral infections.

2) Germinal centers are found in:

a) White pulp follicles

b) Red pulp cords

c) Capsule

d) Sinusoids

Explanation: B-cells proliferate and differentiate in germinal centers of white pulp follicles. Correct answer: White pulp follicles. Clinical: hyperactive germinal centers can occur in autoimmune diseases.

3) Plasma cells are abundant in:

a) Red pulp

b) White pulp

c) Capsule

d) PALS

Explanation: Plasma cells derived from B-cells are mainly in Billroth’s cords of red pulp. Correct answer: Red pulp. Clinical: splenic damage reduces antibody production.

4) Marginal zone of spleen contains:

a) Specialized B-cells

b) T-cells

c) Macrophages only

d) Capsule fibroblasts

Explanation: Marginal zone surrounds white pulp and contains specialized B-cells and macrophages. Correct answer: Specialized B-cells. Clinical: marginal zone lymphoma arises from these B-cells.

5) White pulp to red pulp ratio is approximately:

a) 1:3

b) 3:1

c) 1:1

d) 2:1

Explanation: Red pulp predominates (~3:1) over white pulp. Correct answer: 1:3. Clinical: splenomegaly increases red pulp proportion, affecting blood filtration.

6) Spleen's immune response to blood-borne antigens is mediated by:

a) White pulp B-cells

b) Red pulp macrophages

c) Capsule fibroblasts

d) Sinusoids

Explanation: White pulp B-cells produce antibodies in response to blood-borne antigens. Correct answer: White pulp B-cells. Clinical: asplenic patients have impaired humoral immunity.

7) Central arteries in spleen are surrounded by:

a) PALS

b) Billroth’s cords

c) Capsule

d) Sinusoids

Explanation: Central arteries are encircled by T-cell rich PALS in white pulp. Correct answer: PALS. Clinical: PALS destruction may impair cell-mediated immunity.

8) Billroth’s cords contain:

a) Macrophages, plasma cells, lymphocytes

b) Only erythrocytes

c) Fibroblasts only

d) Collagen fibers only

Explanation: Billroth’s cords in red pulp contain macrophages, plasma cells, and lymphocytes. Correct answer: Macrophages, plasma cells, lymphocytes. Clinical: damage to cords impairs clearance of aged RBCs.

9) Spleen functions include all except:

a) Filtering blood

b) Producing antibodies

c) Hematopoiesis in adult

d) Destroying aged RBCs

Explanation: Spleen filters blood, produces antibodies, and removes aged RBCs. Adult hematopoiesis is minimal. Correct answer: Hematopoiesis in adult. Clinical: extramedullary hematopoiesis can occur in disease.

10) Accessory spleens contain:

a) Both white and red pulp

b) Only white pulp

c) Only red pulp

d) Capsule only

Explanation: Accessory spleens contain both red and white pulp, functioning like main spleen. Correct answer: Both white and red pulp. Clinical: important in splenectomy to prevent recurrence of hematologic disease.

Keyword Definitions

• Spleen – Lymphoid organ in left upper abdomen; filters blood, immune surveillance, stores blood.

• White pulp – Lymphoid tissue surrounding central arteries; contains lymphocytes; immune function.

• Red pulp – Vascular sinusoids and cords; removes aged RBCs, stores platelets.

• Billroth’s cords – Also called splenic cords; connective tissue strands in red pulp containing macrophages, lymphocytes, and plasma cells.

• Central artery – Penetrates white pulp; surrounded by periarteriolar lymphoid sheath (PALS).

• Splenic sinusoids – Vascular channels in red pulp; allow filtration of blood cells.

• Capsule – Dense connective tissue surrounding spleen; provides protection and structure.

• Clinical relevance – Splenic injury affects hematological and immune function; red pulp disorders cause anemia.

• Embryology – Spleen develops from mesenchymal cells in dorsal mesogastrium during 5th week.

• Histology – Red pulp: cords and sinusoids; White pulp: lymphoid follicles with germinal centers.

Chapter: Histology / Embryology

Topic: Lymphoid Organs

Subtopic: Spleen Structure and Components

Lead Question – 2013

Billroth's cord are present in which part of spleen?

a) White pulp

b) Red pulp

c) Both

d) Capsule

Explanation: Billroth’s cords are connective tissue strands found in the red pulp of the spleen, containing macrophages, lymphocytes, plasma cells, and reticular fibers. Correct answer: Red pulp. They function in filtration and immune surveillance. White pulp contains lymphoid follicles; capsule is protective connective tissue. Damage can impair hematological and immune functions.

Guessed Questions for NEET PG

1) Central arteries are found in:

a) White pulp

b) Red pulp

c) Both

d) Capsule

Explanation: Central arteries pass through white pulp surrounded by periarteriolar lymphoid sheath (PALS). Correct answer: White pulp. Clinical: arterial occlusion can reduce immune cell activation.

2) Splenic sinusoids are located in:

a) Red pulp

b) White pulp

c) Capsule

d) Trabeculae

Explanation: Sinusoids are vascular channels in red pulp facilitating filtration of aged or damaged RBCs. Correct answer: Red pulp. Clinical: sinusoidal damage can lead to hemolytic anemia.

3) Periarteriolar lymphoid sheath (PALS) surrounds:

a) Central arteries

b) Red pulp cords

c) Capsule

d) Sinusoids

Explanation: PALS consists of T-lymphocytes surrounding central arteries in white pulp. Correct answer: Central arteries. Clinical: immune deficiencies can impair T-cell mediated responses.

4) Germinal centers are present in:

a) White pulp follicles

b) Red pulp

c) Capsule

d) Sinusoids

Explanation: Germinal centers in white pulp follicles are sites of B-cell proliferation and differentiation. Correct answer: White pulp. Clinical: germinal center hyperplasia occurs in infections or autoimmune diseases.

5) Trabeculae of spleen contain:

a) Connective tissue and vessels

b) White pulp only

c) Red pulp only

d) Sinusoids only

Explanation: Trabeculae provide structural support, carrying arteries and veins into spleen. Correct answer: Connective tissue and vessels. Clinical: trauma can rupture trabeculae, causing hemorrhage.

6) Macrophages in red pulp function to:

a) Phagocytose aged RBCs

b) Produce antibodies

c) Secrete collagen

d) Form germinal centers

Explanation: Macrophages in Billroth’s cords phagocytose old erythrocytes and pathogens. Correct answer: Phagocytose aged RBCs. Clinical: macrophage dysfunction leads to splenomegaly and anemia.

7) White pulp is rich in:

a) Lymphocytes

b) Erythrocytes

c) Platelets

d) Sinusoids

Explanation: White pulp contains lymphocytes around central arteries for immune surveillance. Correct answer: Lymphocytes. Clinical: loss leads to immunodeficiency.

8) Red pulp ratio to white pulp is approximately:

a) 3:1

b) 1:1

c) 1:3

d) 2:1

Explanation: Red pulp constitutes roughly 3/4 of splenic volume, responsible for filtration and blood storage. Correct answer: 3:1. Clinical: splenomegaly increases red pulp proportion causing anemia.

9) Capsule of spleen is composed of:

a) Dense connective tissue

b) Lymphoid tissue

c) Sinusoids

d) Cartilage

Explanation: Capsule is dense connective tissue surrounding spleen, providing protection and support. Correct answer: Dense connective tissue. Clinical: splenic rupture involves capsule laceration.

10) Accessory spleens are usually located near:

a) Hilum

b) Red pulp

c) White pulp

d) Capsule

Explanation: Accessory spleens develop near hilum, containing red and white pulp. Correct answer: Hilum. Clinically important in splenectomy to remove all functional splenic tissue.

Chapter: Head & Neck — Topic: Lymphatics — Subtopic: Retropharyngeal & Neck Nodes

Keywords:

• Rouviere nodes — Group of lateral retropharyngeal lymph nodes at the base of skull (often clinically important in nasopharyngeal carcinoma).

• Retropharyngeal nodes — Nodes located in the retropharyngeal space behind the pharynx; drain nasopharynx and nasal cavities.

• Nasopharynx — Upper part of pharynx behind the nasal cavity; common site for carcinoma with retropharyngeal nodal spread.

• Level II nodes — Upper jugular group; important neck nodes for head & neck cancers.

• Deep cervical chain — Major lymphatic drainage pathway along the internal jugular vein.

• Clavicular nodes — Supraclavicular nodes at the thoracic inlet; signal advanced disease if involved.

• Oral cavity nodes — Drain oral structures; different pattern from nasopharyngeal drainage.

• Imaging — CT/MRI used to detect retropharyngeal (Rouviere) nodes in head & neck cancer staging.

• Nodes of Rouviere clinical relevance — Key for staging nasopharyngeal carcinoma and planning radiotherapy fields.

• Jugulodigastric node — Prominent upper deep cervical node often involved in oropharyngeal infections and cancers.

Lead Question – 2012

1. Rouviere nodes are situated in ?
a) Nasopharynx
b) Oral cavity
c) Retropharynx
d) Clavicular nodes

Explanation: Rouviere nodes are lateral retropharyngeal lymph nodes located in the retropharyngeal space near the base of skull; they receive lymph from the nasopharynx and are clinically important in nasopharyngeal carcinoma staging. Therefore the correct answer is c) Retropharynx. (50 words)

2. Enlargement of Rouviere nodes most commonly suggests primary pathology in the:
a) Oral cavity
b) Nasopharynx
c) Larynx
d) Thyroid

Explanation: Rouviere (lateral retropharyngeal) nodes drain the nasopharynx and posterior nasal cavity; their enlargement often indicates nasopharyngeal infection or malignancy rather than oral cavity, larynx, or thyroid disease. This makes nasopharynx the most likely primary site. Correct answer: b) Nasopharynx. (50 words)

3. Best imaging modality to detect Rouviere nodes in suspected nasopharyngeal carcinoma is:
a) Chest X-ray
b) CT/MRI of head & neck
c) Abdominal ultrasound
d) PET only

Explanation: CT and MRI of the head and neck visualize soft tissue extent and retropharyngeal nodes including Rouviere nodes for staging nasopharyngeal cancer; PET may complement for metabolic activity but CT/MRI are primary for anatomic delineation. Correct answer: b) CT/MRI of head & neck. (50 words)

4. In radiation planning for nasopharyngeal carcinoma, Rouviere nodes are included because they are located in the:
a) Parotid gland region
b) Lateral retropharyngeal space near skull base
c) Anterior cervical triangle
d) Supraclavicular fossa

Explanation: Rouviere nodes sit in the lateral retropharyngeal space by the skull base and are common sites of microscopic spread in nasopharyngeal carcinoma; hence radiotherapy fields include this region. They are not in parotid, anterior triangle, or supraclavicular fossa. Correct answer: b) Lateral retropharyngeal space near skull base. (50 words)

5. Clinically palpable Rouviere nodes are:
a) Common on routine neck exam
b) Deep and usually not palpable unless markedly enlarged
c) Always tender in malignancy
d) Located superficially over sternocleidomastoid

Explanation: Rouviere nodes lie deep in the retropharyngeal space and are not palpable on routine exam; they become clinically evident only when significantly enlarged from infection or tumor. They are deep, not superficial or routinely tender in malignancy. Correct answer: b) Deep and usually not palpable unless markedly enlarged. (50 words)

6. Surgical access to enlarged Rouviere nodes for biopsy is most safely performed via:
a) Transoral approach without imaging guidance
b) Image-guided deep neck biopsy or endoscopic nasopharyngeal biopsy
c) Supraclavicular incision
d) Submandibular incision

Explanation: Due to deep location adjacent to skull base and vital structures, Rouviere nodes are best assessed by image-guided biopsy or endoscopic nasopharyngeal sampling; blind transoral or superficial neck incisions risk injury. Correct answer: b) Image-guided deep neck biopsy or endoscopic nasopharyngeal biopsy. (50 words)

7. Which statement about retropharyngeal space and nodes is TRUE?
a) Retropharyngeal nodes drain anterior chest primarily
b) Retropharyngeal space communicates with mediastinum allowing spread of infection
c) Retropharyngeal nodes are superficial neck nodes
d) Retropharyngeal nodes drain lower limb lymph

Explanation: The retropharyngeal space can extend into the posterior mediastinum, permitting downward spread of infection from the neck to chest; Rouviere nodes reside in this space. They do not drain chest primarily, are not superficial, nor related to lower limb drainage. Correct answer: b) Retropharyngeal space communicates with mediastinum allowing spread of infection. (50 words)

8. On MRI a metastatic Rouviere node typically shows which feature?
a) Small, fatty hilum preserved
b) Enlarged node with necrosis or contrast enhancement
c) Calcified only
d) Identical to normal muscle tissue

Explanation: Metastatic retropharyngeal nodes often enlarge and may show central necrosis and irregular contrast enhancement on MRI/CT, distinguishing them from reactive nodes which retain fatty hilum. Calcification is uncommon; they are not identical to muscle. Correct answer: b) Enlarged node with necrosis or contrast enhancement. (50 words)

9. Which tumor most commonly metastasizes to Rouviere nodes?
a) Nasopharyngeal carcinoma
b) Thyroid carcinoma exclusively
c) Cutaneous melanoma of leg only
d) Wilms tumor

Explanation: Nasopharyngeal carcinoma commonly spreads to retropharyngeal (Rouviere) nodes early due to lymphatic drainage pathways; thyroid and distal cutaneous tumors less commonly involve these nodes. Thus nasopharyngeal carcinoma is the most frequent primary causing Rouviere node metastasis. Correct answer: a) Nasopharyngeal carcinoma. (50 words)

10. Retropharyngeal abscess presenting with neck stiffness and dysphagia may involve which nodes? a) Submandibular nodes
b) Rouviere (retropharyngeal) nodes
c) Occipital nodes only
d) Inguinal nodes

Explanation: Retropharyngeal abscesses involve the retropharyngeal space and its nodes (including Rouviere nodes), causing dysphagia, neck stiffness, and potential airway compromise; prompt imaging and drainage are needed. Submandibular or distant nodes are not primary in this condition. Correct answer: b) Rouviere (retropharyngeal) nodes. (50 words)

11. Which clinical finding warrants evaluation of Rouviere nodes in an adult patient?
a) Persistent unilateral serous otitis media and nasopharyngeal mass suspicion
b) Bilateral ankle swelling only
c) Chronic cough without ENT symptoms
d) Isolated carpal tunnel syndrome

Explanation: Persistent unilateral serous otitis media in adults may signal nasopharyngeal carcinoma obstructing the Eustachian tube; evaluation must include imaging of Rouviere nodes and nasopharynx. Distant systemic symptoms without ENT signs do not directly implicate these nodes. Correct answer: a) Persistent unilateral serous otitis media and nasopharyngeal mass suspicion. (50 words)

Chapter: Obstetrics & Gynecology

Topic: Female Pelvic Anatomy & Oncology

Subtopic: Lymphatic Drainage of Cervix & Clinical Implications

Keywords (Definitions)

• Cervix: Lower part of uterus opening into the vagina; key site for HPV-related malignancy.

• Lymphatic drainage: Network conveying lymph from tissues to regional lymph nodes.

• Iliac lymph nodes: Pelvic nodes along external, internal, and common iliac vessels receiving cervical lymph.

• External iliac nodes: Nodes along external iliac vessels; frequent first-echelon nodes from cervix.

• Internal iliac (hypogastric) nodes: Pelvic nodes draining cervix via paracervical pathways.

• Obturator nodes: Nodes in obturator fossa around obturator nerve; common sentinel basin.

• Sacral nodes: Lateral/ presacral nodes receiving posterior cervical lymph.

• Para-aortic (lumbar) nodes: Nodes along aorta; second-echelon or advanced spread from pelvis.

• Inguinal nodes (superficial/deep): Groin nodes; drain vulva and lower third of vagina, not primary cervix.

• Sentinel lymph node (SLN): First draining node(s) from a tumor; used for targeted sampling/mapping.

• FIGO 2018 IIIC stage: Cervical cancer staging: IIIC1 pelvic node metastasis; IIIC2 para-aortic.

• PET-CT: Imaging modality sensitive for nodal metastasis, especially para-aortic.

• Upper vs lower vagina drainage: Upper to pelvic nodes; lower to inguinal nodes.

• Radical hysterectomy (Type C1): Nerve-sparing resection with parametrial and pelvic lymphadenectomy.

• Lymphocyst: Post-lymphadenectomy lymph collection in pelvis/retroperitoneum.

• Obturator nerve: Landmark within obturator fossa; guides identification of obturator nodes.

• 
  

Lead Question - 2012

Lymphatic drainage of cervix is to

a) Iliac lymph nodes
b) Para aortic lymph nodes
c) Superficial inguinal lymph nodes
d) Deep inguinal lymph nodes

Explanation (≈50 words): The primary lymphatic drainage of the cervix is to the pelvic (iliac) nodal groups—obturator, internal iliac, external iliac, and sacral. Inguinal nodes drain the lower third of the vagina and vulva; para-aortic nodes are second-echelon spread. Answer: a) Iliac lymph nodes.

Guessed MCQ 1

A 36-year-old with FIGO IA2 cervical cancer undergoes SLN mapping. Which tracer has the best bilateral detection in experienced hands?

a) Indigo carmine
b) Indocyanine green (ICG)
c) Trypan blue
d) Methylene blue

Explanation (≈50 words): Indocyanine green with near-infrared imaging achieves high bilateral sentinel detection and low false-negative rates in early cervical cancer. Blue dyes alone have lower sensitivity. Technetium may be combined but ICG is widely preferred for real-time visualization. Answer: b) Indocyanine green (ICG).

Guessed MCQ 2

First-echelon nodal basin most commonly involved in carcinoma cervix is

a) Popliteal nodes
b) Axillary nodes
c) Obturator nodes
d) Deep inguinal nodes

Explanation: Lymph from the cervix passes through paracervical channels to obturator and internal/external iliac nodes. Obturator nodes in the obturator fossa are the commonest first-echelon group sampled during pelvic lymphadenectomy or SLN biopsy. Popliteal and axillary nodes are unrelated; deep inguinal nodes drain lower limb and perineum. Answer: c) Obturator nodes.

Guessed MCQ 3 (Clinical)

A 48-year-old with bulky cervical mass has PET-CT showing FDG-avid common iliac nodes but no para-aortic uptake. FIGO 2018 stage is

a) IIB
b) IIIC1
c) IIIC2
d) IVA

Explanation: Nodal staging in FIGO 2018 classifies pelvic nodal metastasis (including common iliac) as stage IIIC1, while para-aortic nodal involvement is IIIC2. Local parametrial involvement defines IIB, and invasion of adjacent organs bladder/rectum indicates IVA. Here only pelvic nodes are positive. Answer: b) IIIC1.

Guessed MCQ 4 (Clinical)

A patient with cervical cancer and lower third vaginal involvement is likely to have additional drainage to

a) Superficial inguinal nodes
b) Mediastinal nodes
c) Popliteal nodes
d) Epitrochlear nodes

Explanation: The lower third of the vagina drains to superficial inguinal nodes, creating a pathway for groin metastasis when the disease extends inferiorly. Mediastinal, popliteal, and epitrochlear nodes are not involved in genital tract drainage. Hence groin evaluation is important if the lower vagina is affected. Answer: a) Superficial inguinal nodes.

Guessed MCQ 5 (Clinical)

Post-radical hysterectomy, histology shows metastasis in para-aortic nodes only. FIGO 2018 stage is

a) IIIC1
b) IIIC2
c) IIIA
d) IVB

Explanation: Isolated para-aortic nodal metastasis without distant organ spread upgrades to FIGO IIIC2. IIIC1 denotes pelvic nodal disease. IIIA involves lower vaginal invasion; IVB implies distant metastases beyond the abdomen/pelvis (e.g., lung, bone). Para-aortic positivity alone fits IIIC2. Answer: b) IIIC2.

Guessed MCQ 6

Best single imaging modality to detect occult para-aortic nodal metastasis pre-treatment in cervical cancer

a) Pelvic ultrasound
b) PET-CT
c) Plain CT
d) Chest X-ray

Explanation (≈50 words): PET-CT outperforms CT and MRI for detecting metabolically active nodal metastases, particularly in para-aortic chains, guiding field extension for chemoradiation. Ultrasound and chest X-ray lack sensitivity for retroperitoneal nodal disease. Tissue confirmation may still be required when management will change. Answer: b) PET-CT.

Guessed MCQ 7

Primary lymphatic drainage of the upper vagina is mainly to

a) External/internal iliac nodes
b) Superficial inguinal nodes
c) Axillary nodes
d) Popliteal nodes

Explanation: The upper two-thirds of the vagina drain predominantly to the internal and external iliac nodes, paralleling cervical drainage. The lower third drains to the superficial inguinal nodes. Axillary and popliteal nodes are unrelated to pelvic genital tract lymphatics. Answer: a) External/internal iliac nodes.

Guessed MCQ 8

Which surgical procedure routinely addresses parametrial tissue and pelvic nodes in operable cervical cancer?

a) Simple hysterectomy
b) Radical hysterectomy (Type C1, nerve-sparing)
c) Myomectomy
d) Endometrial ablation

Explanation: Radical hysterectomy Type C1 (Querleu–Morrow) removes uterus with parametria and includes pelvic lymphadenectomy while preserving pelvic nerves. Simple hysterectomy lacks adequate margins and nodal assessment; myomectomy and ablation are not oncologic procedures. Answer: b) Radical hysterectomy (Type C1, nerve-sparing).

Guessed MCQ 9

Posterior cervical lymph primarily drains to which nodal group?

a) Presacral/lateral sacral nodes
b) Axillary nodes
c) Epitrochlear nodes
d) Deep inguinal nodes

Explanation: The posterior cervix drains via uterosacral pathways to presacral and lateral sacral nodes, part of the pelvic (iliac–sacral) chains. Axillary and epitrochlear nodes are upper-limb related; deep inguinal nodes pertain to lower limb and perineum. Answer: a) Presacral/lateral sacral nodes.

Guessed MCQ 10 (Clinical)

After pelvic lymphadenectomy for early cervical cancer, a patient develops a painless pelvic mass causing leg edema. Most likely complication is

a) Hematoma
b) Lymphocyst
c) Abscess
d) Seroma from abdominal wall

Explanation: Disruption of pelvic lymphatics can lead to lymphocyst formation—an encapsulated lymph collection in the retroperitoneum causing mass effect and lower-limb edema or hydronephrosis. Hematoma or abscess are typically painful and inflammatory; abdominal wall seroma is superficial. Answer: b) Lymphocyst.

Guessed MCQ 11

During node dissection, which anatomic landmark confirms entry into the obturator fossa containing the obturator nodal packet?

a) Femoral artery
b) Obturator nerve
c) Round ligament
d) Ureteric orifice

Explanation: The obturator nerve traverses the obturator fossa and serves as a key landmark for identifying and clearing obturator nodes during pelvic lymphadenectomy. Femoral artery is outside the pelvis; round ligament is anterior; ureteric orifice relates to bladder trigone, not the obturator space. Answer: b) Obturator nerve.

Chapter: Head & Neck Anatomy  |  Topic: Nasal Cavity & Paranasal Sinuses  |  Subtopic: Lymphatic Drainage of Nose

Keyword Definitions

• Lateral wall of nose: Side wall bearing turbinates and meati.

• Submandibular nodes: Level Ib nodes draining anterior nasal cavity/vestibule.

• Retropharyngeal nodes: Nodes behind pharynx draining posterior nasal cavity.

• Deep cervical nodes: Jugular chain receiving lymph from head & neck.

• Anterior nasal cavity: Area near vestibule, drains anteroinferiorly.

• Posterior nasal cavity: Choanal region, drains to retropharyngeal/deep cervical.

• Kiesselbach’s area: Vascular plexus on anterior septum.

• Waldeyer’s ring: Lymphoid ring around naso-oropharynx.

• Level II nodes: Upper jugular nodes under sternomastoid.

• Sentinel node: First draining node from a primary site.

Lead Question – 2012

Lymphatic drainage of lateral wall of nose

a) Submandibular nodes
b) Retropharyngeal nodes
c) Deep cervical nodes
d) All of the above

Explanation (Answer: d)

Anterior parts of the lateral nasal wall drain to submandibular nodes, while posterior parts drain to retropharyngeal nodes; both channels ultimately reach the deep cervical chain. Hence all listed groups participate in drainage depending on subsite, making “All of the above” the correct option for comprehensive lateral wall drainage.

2) Posterior lateral nasal wall carcinoma most classically first drains to:

a) Submental nodes
b) Retropharyngeal nodes
c) Supraclavicular nodes
d) Occipital nodes

Explanation (Answer: b)

Posterior nasal cavity, including posterior lateral wall near choanae, frequently drains to retropharyngeal nodes before reaching the upper deep cervical chain. Submental drainage is for lower lip/anterior floor of mouth, supraclavicular for lower neck catchment, and occipital for posterior scalp.

3) Which statement about lymphatics of the nasal cavity is MOST accurate?

a) All nasal subsites drain only to submental nodes
b) Anterior subsites favor submandibular drainage
c) Posterior subsites drain only to Level IV
d) Lymph bypasses deep cervical nodes

Explanation (Answer: b)

Anterior nasal cavity, including vestibule and inferior meatus region, commonly drains to submandibular nodes. Posterior subsites use retropharyngeal and then deep cervical chains. Deep cervical involvement is common; exclusive Level IV or submental drainage is incorrect. Thus, anterior-to-submandibular is the most accurate.

4) A clinician suspects retropharyngeal nodal disease in a posterior choanal mass. The next echelon typically involved is:

a) Level II deep cervical nodes
b) Pretracheal nodes
c) Submental nodes
d) Parotid nodes

Explanation (Answer: a)

Posterior nasal cavity drains to retropharyngeal nodes, then commonly to upper deep cervical (Level II) nodes along the internal jugular chain. Pretracheal nodes are for lower airway/thyroid regions, submental for lower lip/anterior floor, and parotid for lateral face/scalp anterior to ear.

5) In epistaxis originating from anterior lateral wall near the vestibule, which nodal basin most likely shows reactive enlargement?

a) Level II nodes
b) Submandibular nodes
c) Level IV nodes
d) Retropharyngeal nodes

Explanation (Answer: b)

Inflammation or infection in anterior lateral nasal wall/vestibule commonly drains to submandibular nodes, which may become reactive. Retropharyngeal nodes are more posterior. Level II may be secondary, and Level IV is a lower jugular station not typically first involved in anterior nasal pathology.

6) A 42-year-old with posterior lateral nasal wall tumor has occult nodal spread. Which imaging-detected node best supports expected drainage?

a) Retropharyngeal node behind pharyngeal wall
b) Submental node below chin
c) Level V posterior triangle node
d) Supraclavicular node

Explanation (Answer: a)

Posterior lateral nasal wall drains to retropharyngeal nodes first. Submental, Level V, and supraclavicular nodes are not typical initial stations for nasal cavity primaries. Finding a retropharyngeal metastasis aligns with the anatomical lymphatic pathways of posterior nasal subsites.

7) Which subsite pairing is CORRECT regarding primary lymphatic drainage?

a) Anterior lateral wall → Submandibular nodes
b) Posterior lateral wall → Submental nodes
c) Anterior lateral wall → Retropharyngeal nodes
d) Posterior lateral wall → Occipital nodes

Explanation (Answer: a)

Anterior lateral wall and vestibule drain to submandibular nodes. Posterior lateral wall prefers retropharyngeal and then deep cervical nodes. Submental and occipital nodal groups are not the primary drainage for these nasal subsites, making option a the accurate pairing.

8) A child with posterior nasal infection develops torticollis and fever. Which node is classically implicated?

a) Retropharyngeal node (suppurative adenitis)
b) Submandibular node
c) Preauricular node
d) Level IV node

Explanation (Answer: a)

Retropharyngeal nodes drain the posterior nasal cavity and nasopharynx; suppurative adenitis can present with neck stiffness/torticollis and fever in children. Submandibular nodes typically reflect anterior oral/nasal infections. Preauricular and Level IV nodes are not the classical primary sites for posterior nasal infections.

9) For surgical planning in anterior lateral nasal wall cancer, which selective neck dissection levels are MOST relevant initially?

a) Levels I–III (emphasis on Level Ib)
b) Levels IV–V only
c) Level VI central compartment
d) Parotidectomy with Level V only

Explanation (Answer: a)

Anterior lateral wall tends to involve submandibular (Level Ib) first, with potential spread to Levels II–III. Levels IV–V are lower/posterior and less commonly initial. Level VI pertains to central compartment organs. Parotidectomy targets preauricular/parotid nodes, not primary anterior nasal drainage.

10) Which statement about deep cervical nodes in nasal drainage is TRUE?

a) They are never involved in nasal malignancies
b) They receive efferents from both submandibular and retropharyngeal nodes
c) They drain only the scalp and ear
d) They are equivalent to supraclavicular nodes exclusively

Explanation (Answer: b)

Deep cervical nodes (jugular chain) are final common pathways for multiple head-neck subsites. They receive efferents from submandibular and retropharyngeal nodes and are often involved in nasal malignancies. They do not exclusively serve scalp/ear, nor are they limited to supraclavicular territory.

11) A 60-year-old with recurrent posterior epistaxis and fullness behind the soft palate shows a node of Rouvière on MRI. Primary site drainage suggests:

a) Anterior vestibular lesion
b) Posterior lateral nasal wall involvement
c) External nasal skin carcinoma
d) Floor of mouth lesion

Explanation (Answer: b)

Node of Rouvière is the lateral retropharyngeal node, commonly receiving lymph from nasopharynx and posterior nasal cavity, including posterior lateral wall. Anterior vestibule and external nasal skin drain anteriorly to submandibular/preauricular nodes, while floor of mouth drains to submental/submandibular, not retropharyngeal.

Chapter: Abdomen
Topic: Spleen
Subtopic: Surface Anatomy

Keyword Definitions:

• Spleen: Largest lymphoid organ, located in the left hypochondrium.

• Surface Anatomy: Study of external landmarks that indicate internal structures.

• Ribs: Bony framework of thorax, important landmarks for organ projection.

Lead Question - 2012

Spleen extends from ?

a) 5th to 9th rib
b) 9th to 11th rib
c) 2nd to 5th rib
d) 11th to 12th rib

Explanation: The spleen lies in the left hypochondrium, deep to ribs 9–11 along the midaxillary line. Its long axis is parallel to the 10th rib. Correct Answer: b) 9th to 11th rib.

Guessed Question 1

The hilum of the spleen is located on which surface?

a) Diaphragmatic surface
b) Visceral surface
c) Inferior border
d) Superior border

Explanation: The hilum is present on the visceral surface where splenic vessels and lymphatics enter and leave. It is an important landmark for surgical procedures. Correct Answer: b) Visceral surface.

Guessed Question 2

Splenic artery is a branch of?

a) Celiac trunk
b) Superior mesenteric artery
c) Inferior mesenteric artery
d) Renal artery

Explanation: The splenic artery is a tortuous branch of the celiac trunk. It supplies the spleen, pancreas, and part of the stomach. Correct Answer: a) Celiac trunk.

Guessed Question 3

Which ligament connects the spleen to the stomach?

a) Gastrosplenic ligament
b) Splenorenal ligament
c) Phrenicocolic ligament
d) Hepatogastric ligament

Explanation: The gastrosplenic ligament connects the spleen to the greater curvature of the stomach and contains short gastric vessels. Correct Answer: a) Gastrosplenic ligament.

Guessed Question 4

Accessory spleens are most commonly found in?

a) Splenorenal ligament
b) Mesentery
c) Greater omentum
d) Pancreatic tail

Explanation: Accessory spleens are usually found near the splenic hilum or in the splenorenal ligament. They may mimic pathology in imaging. Correct Answer: a) Splenorenal ligament.

Guessed Question 5

In splenomegaly, spleen enlarges along the axis of?

a) 8th rib
b) 9th rib
c) 10th rib
d) 11th rib

Explanation: Splenomegaly causes the spleen to enlarge obliquely downward and medially along the 10th rib. This helps differentiate from renal enlargement. Correct Answer: c) 10th rib.

Guessed Question 6

Splenic vein joins with which vessel to form the portal vein?

a) Superior mesenteric vein
b) Inferior mesenteric vein
c) Left gastric vein
d) Right gastric vein

Explanation: The splenic vein unites with the superior mesenteric vein to form the portal vein behind the neck of the pancreas. Correct Answer: a) Superior mesenteric vein.

Guessed Question 7

Which of the following is NOT a relation of the spleen?

a) Left kidney
b) Stomach
c) Left colic flexure
d) Right adrenal gland

Explanation: The spleen is related to the stomach, left kidney, pancreas, and left colic flexure. The right adrenal gland lies on the opposite side. Correct Answer: d) Right adrenal gland.

Guessed Question 8

During trauma, spleen rupture leads to bleeding into?

a) Peritoneal cavity
b) Pleural cavity
c) Retroperitoneal space
d) Mediastinum

Explanation: Rupture of the spleen results in intraperitoneal hemorrhage, often massive, requiring immediate intervention. Correct Answer: a) Peritoneal cavity.

Guessed Question 9

Splenectomy most commonly predisposes a patient to infections by?

a) Gram-negative bacilli
b) Encapsulated organisms
c) Anaerobic bacteria
d) Mycobacteria

Explanation: Post-splenectomy, patients are more prone to infections with encapsulated bacteria such as Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae. Correct Answer: b) Encapsulated organisms.

Guessed Question 10

Which hematological condition is splenectomy most useful in?

a) Thalassemia major
b) Sickle cell anemia
c) Hereditary spherocytosis
d) Iron deficiency anemia

Explanation: Splenectomy is indicated in hereditary spherocytosis as the spleen destroys the abnormal red cells. Correct Answer: c) Hereditary spherocytosis.

Thoracic Duct: Main lymphatic vessel draining lymph from the majority of the body into the venous system.

Lymphatic System: Network of vessels and nodes that drain interstitial fluid, transport immune cells, and absorb fats from the gut.

Vertebral Levels: Anatomical reference points of vertebrae; T2-T12 are thoracic vertebrae levels.

Lymph Drainage: Thoracic duct drains lymph from left side of body, including left upper limb, thorax, and lower limbs.

Right-to-Left Crossing: Point where thoracic duct crosses midline from right to left before draining into venous circulation at left venous angle.

Chapter: Lymphatic System

Topic: Thoracic Duct Anatomy

Subtopic: Thoracic Duct Course and Vertebral Levels

Lead Question 2012: The thoracic duct crosses from the right to the left at the level of

a) T12 vertebra

b) T6 vertebra

c) T5 vertebra

d) T2 vertebra

Answer: c) T5 vertebra

Explanation: The **thoracic duct** begins at the cisterna chyli and ascends through the thorax on the right side of the vertebral column. It crosses from right to left at approximately the **T5 vertebral level** before draining into the **left venous angle**. This anatomical landmark is important in thoracic surgery and central venous catheter placement to avoid injury to the duct.

1. Where does the thoracic duct drain its lymph?

a) Right subclavian vein

b) Left venous angle

c) Right atrium

d) Thoracic cavity

Answer: b) Left venous angle

Explanation: The **thoracic duct** drains lymph into the **left venous angle**, formed by the junction of the **left internal jugular and subclavian veins**. This drainage allows return of lymph to the systemic circulation, maintaining fluid balance and immune function.

2. The thoracic duct originates from:

a) Thoracic aorta

b) Cisterna chyli

c) Right lymphatic duct

d) Sternal lymph nodes

Answer: b) Cisterna chyli

Explanation: The **cisterna chyli**, located at L1-L2 vertebral level, serves as the origin of the thoracic duct. It collects lymph from the **lower limbs, pelvic cavity, and abdomen**, which then ascends through the thorax to drain into the venous system.

3. The thoracic duct passes through which opening of the diaphragm?

a) Aortic hiatus

b) Caval opening

c) Esophageal hiatus

d) None

Answer: a) Aortic hiatus

Explanation: The **thoracic duct** ascends from the abdomen into the thorax via the **aortic hiatus** of the diaphragm at the T12 level. Understanding its course prevents injury during thoracoabdominal procedures.

4. Clinical significance of thoracic duct injury includes:

a) Pleural effusion

b) Chylothorax

c) Pulmonary embolism

d) Pneumothorax

Answer: b) Chylothorax

Explanation: Injury to the thoracic duct can lead to **chylothorax**, accumulation of lymph in the pleural cavity. It occurs post-thoracic or neck surgery. Knowledge of the crossing at T5 and drainage into the left venous angle is crucial for surgical prevention.

5. On which side of the vertebral column does the thoracic duct ascend initially?

a) Left

b) Right

c) Midline

d) Alternating sides

Answer: b) Right

Explanation: The thoracic duct initially ascends **on the right side** of the vertebral column from the cisterna chyli and crosses to the left at **T5 level**. Awareness of this anatomy is essential during mediastinal and esophageal surgeries to prevent duct injury.

6. The thoracic duct carries lymph from all except:

a) Right upper limb

b) Left lower limb

c) Abdomen

d) Left thorax

Answer: a) Right upper limb

Explanation: The **right upper limb, right thorax, and right head and neck** are drained by the **right lymphatic duct**, while the thoracic duct drains **all left-sided regions and lower body**. This distinction is important for understanding lymphatic drainage patterns.

7. The thoracic duct terminates at:

a) Left brachiocephalic vein

b) Left subclavian vein

c) Left venous angle

d) Right venous angle

Answer: c) Left venous angle

Explanation: The thoracic duct empties into the **left venous angle**, the junction of the **left internal jugular and subclavian veins**. This allows lymph to re-enter the venous circulation efficiently.

8. Which vertebral level corresponds to the cisterna chyli?

a) T12

b) L1-L2

c) T5

d) L3-L4

Answer: b) L1-L2

Explanation: The **cisterna chyli** lies at **L1-L2**, serving as the origin of the thoracic duct. It collects lymph from the abdomen and lower limbs before ascending through the thorax.

9. Which imaging modality best visualizes the thoracic duct?

a) Ultrasound

b) MRI lymphangiography

c) X-ray

d) PET scan

Answer: b) MRI lymphangiography

Explanation: **MRI lymphangiography** provides high-resolution imaging of the thoracic duct, its course, and any obstructions or injuries, which is valuable in planning surgery or treating chylothorax.

10. Surgical injury to thoracic duct at T5 level may cause:

a) Chylopericardium

b) Chylothorax

c) Ascites

d) Pulmonary edema

Answer: b) Chylothorax

Explanation: Injury to the thoracic duct at the **T5 crossing point** can result in **chylothorax**, accumulation of lymph in the pleural cavity. Recognizing its course is essential to avoid this complication during thoracic and esophageal surgery.

Chapter: Anatomy | Topic: Lymphatic System | Subtopic: Axillary Lymph Nodes

Keyword Definitions

• Melanoma – A malignant tumor of melanocytes, often arising in skin.

• Axillary Lymph Nodes – Group of lymph nodes in the armpit that drain lymph from the upper limb, breast, and thoracic wall.

• Apical Lymph Nodes – Nodes located at the apex of the axilla, medial to the pectoralis minor.

• Central Lymph Nodes – Nodes lying in the center of the axilla, receiving drainage from other axillary groups.

• Lateral Lymph Nodes – Nodes along the humeral vessels, draining most lymph from the upper limb.

• Pectoral Lymph Nodes – Nodes along the lateral thoracic vessels, draining anterior thoracic wall and breast.

• Pectoralis Minor Muscle – A thin, triangular muscle in the chest beneath the pectoralis major.

• Lymphatic Drainage – The process of lymph movement through vessels and nodes.

• Lymph Node Dissection – Surgical removal of lymph nodes for cancer treatment or staging.

• Clinical Anatomy – Application of anatomical knowledge to clinical practice.

Lead Question (NEET PG 2012):

A patient is found to have a melanoma originating in the skin of the left forearm. After removal of the tumor from the forearm, all axillary lymph nodes lateral to the medial edge of the pectoralis minor muscle are removed. Which axillary nodes would not be removed?

a) Apical lymph nodes

b) Central lymph nodes

c) Lateral lymph nodes

d) Pectoral lymph nodes

Explanation: The apical lymph nodes lie medial to the pectoralis minor, at the apex of the axilla, and receive lymph from all other axillary groups. In this case, only nodes lateral to the medial border of pectoralis minor are excised, sparing the apical group. Therefore, they would not be removed. Correct answer: a) Apical lymph nodes.

Q2. Which group of axillary lymph nodes primarily drains the upper limb?

a) Lateral lymph nodes

b) Apical lymph nodes

c) Central lymph nodes

d) Pectoral lymph nodes

The lateral (humeral) lymph nodes, located along the humeral vessels, are the main drainage for most of the upper limb. Other groups, such as apical or central nodes, receive secondary drainage. Correct answer: a) Lateral lymph nodes.

Q3. Which axillary node group receives lymph from all other axillary node groups?

a) Central

b) Apical

c) Pectoral

d) Lateral

The apical lymph nodes are located at the apex of the axilla and act as a final collecting point for lymph before it enters the subclavian lymph trunk. Correct answer: b) Apical.

Q4. Lymph from the anterior thoracic wall, including most of the breast, drains first to:

a) Lateral nodes

b) Central nodes

c) Pectoral nodes

d) Apical nodes

The pectoral lymph nodes, situated along the lateral thoracic vessels, are the primary drainage site for the anterior thoracic wall and the majority of the breast. Correct answer: c) Pectoral nodes.

Q5. Which nodes lie centrally in the axilla and receive lymph from lateral, pectoral, and subscapular groups?

a) Central nodes

b) Apical nodes

c) Lateral nodes

d) Infraclavicular nodes

Central lymph nodes act as a hub, collecting lymph from major axillary node groups before passing it to apical nodes. Correct answer: a) Central nodes.

Q6. In a radical mastectomy, which group of axillary nodes is typically removed?

a) Only apical

b) Only pectoral

c) Pectoral, lateral, central, subscapular, and sometimes apical

d) Only lateral

Radical mastectomy involves removal of multiple axillary node groups (pectoral, lateral, central, subscapular) to ensure complete cancer clearance; apical nodes may also be removed if involved. Correct answer: c) Pectoral, lateral, central, subscapular, and sometimes apical.

Q7. Which structure is used as a landmark to divide axillary nodes into levels?

a) Pectoralis major

b) Pectoralis minor

c) Serratus anterior

d) Subclavius

The pectoralis minor muscle is the key landmark. Nodes are classified into Level I (lateral), Level II (posterior), and Level III (medial) relative to this muscle. Correct answer: b) Pectoralis minor.

Q8. Lymph from the skin of the lateral forearm drains primarily into:

a) Cubital nodes → lateral axillary nodes

b) Pectoral nodes directly

c) Central nodes directly

d) Apical nodes directly

Superficial lymphatics from the lateral forearm drain first to cubital lymph nodes and then to lateral axillary nodes for further filtration. Correct answer: a) Cubital nodes → lateral axillary nodes.

Q9. Which axillary node group is located along the subscapular vessels?

a) Lateral

b) Apical

c) Subscapular

d) Central

The subscapular (posterior) nodes lie along the subscapular vessels and drain the posterior thoracic wall and part of the scapular region. Correct answer: c) Subscapular.

Q10. Sentinel lymph node biopsy in breast cancer usually targets which axillary node group first?

a) Pectoral

b) Lateral

c) Central

d) Apical

Sentinel node biopsy identifies the first draining lymph node from the tumor site, often a pectoral node in breast cancer, to assess for metastasis. Correct answer: a) Pectoral.