Keyword Definitions
• Clavipectoral fascia – A strong sheet of connective tissue deep to pectoralis major, enclosing subclavius and pectoralis minor.
• Costocoracoid ligament – Thickened portion of clavipectoral fascia between coracoid process and first rib; origin of fascia.
• Coracoacromial ligament – Connects coracoid process to acromion, prevents superior displacement of humeral head.
• Coracoclavicular ligament – Strong stabilizer between clavicle and coracoid process; prevents clavicle dislocation.
• Costoclavicular ligament – Connects first rib to clavicle, stabilizes sternoclavicular joint.
• Pectoralis minor – Muscle enclosed by clavipectoral fascia, important surgical landmark.
• Subclavius – Small muscle beneath clavicle, enclosed by clavipectoral fascia.
• Axilla – Space under shoulder joint, bounded anteriorly by clavipectoral fascia, important for neurovascular structures.
• Clinical relevance – Thickening or fibrosis of clavipectoral fascia can compress neurovascular bundle in thoracic outlet syndrome.
• Fascia – Connective tissue layers enveloping muscles, vessels, and nerves.
Chapter: Anatomy / Thorax
Topic: Pectoral Region
Subtopic: Clavipectoral Fascia and Ligament Derivation
Lead Question – 2013
Clavipectoral fascia is derived from which ligament?
a) Coracoacromial
b) Coracoclavicular
c) Costoclavicular
d) Costocoracoid
Explanation: Clavipectoral fascia originates from the costocoracoid ligament, extending between the coracoid process and first rib. Correct answer: Costocoracoid ligament. This fascia encloses subclavius and pectoralis minor, forming an important surgical plane. Clinical: In axillary surgeries, the fascia acts as a guide for neurovascular structures, preventing accidental injuries.
Guessed Questions for NEET PG
1) Clavipectoral fascia encloses:
a) Pectoralis major
b) Subclavius and pectoralis minor
c) Serratus anterior
d) Latissimus dorsi
Explanation: The fascia encloses subclavius and pectoralis minor, not pectoralis major. Correct answer: Subclavius and pectoralis minor. Clinical: important in surgical dissection of axilla.
2) Costoclavicular ligament connects:
a) Clavicle to sternum
b) Clavicle to coracoid
c) Clavicle to first rib
d) Coracoid to acromion
Explanation: Costoclavicular ligament stabilizes sternoclavicular joint by attaching clavicle to first rib. Correct answer: Clavicle to first rib. Clinical: damage leads to sternoclavicular instability.
3) Coracoacromial ligament prevents:
a) Inferior displacement of humerus
b) Superior displacement of humeral head
c) Lateral displacement of scapula
d) Medial rotation of clavicle
Explanation: It forms an arch preventing superior displacement of humeral head. Correct answer: Superior displacement of humeral head. Clinical: impingement syndrome occurs beneath this arch.
4) Clavipectoral fascia pierces to transmit:
a) Cephalic vein
b) Axillary vein
c) Subclavian artery
d) Long thoracic nerve
Explanation: Cephalic vein pierces the clavipectoral fascia near deltopectoral groove. Correct answer: Cephalic vein. Clinical: serves as an important venous access site.
5) Axillary sheath is continuous with:
a) Pretracheal fascia
b) Prevertebral fascia
c) Carotid sheath
d) Endothoracic fascia
Explanation: Axillary sheath is extension of prevertebral fascia enclosing axillary vessels and brachial plexus. Correct answer: Prevertebral fascia. Clinical: important in brachial plexus block anesthesia.
6) Subclavius muscle is innervated by:
a) Nerve to subclavius
b) Lateral pectoral nerve
c) Medial pectoral nerve
d) Long thoracic nerve
Explanation: Subclavius is innervated by nerve to subclavius (C5–C6). Correct answer: Nerve to subclavius. Clinical: weakness may cause instability of clavicle in trauma.
7) Pectoralis minor inserts into:
a) Acromion
b) Coracoid process
c) Clavicle
d) Glenoid cavity
Explanation: Pectoralis minor attaches to coracoid process of scapula. Correct answer: Coracoid process. Clinical: hypertrophy or contracture compresses brachial plexus in thoracic outlet syndrome.
8) Which structure lies deep to clavipectoral fascia?
a) Axillary vein
b) Axillary artery
c) Brachial plexus cords
d) All of the above
Explanation: Clavipectoral fascia overlies axillary vessels and brachial plexus cords. Correct answer: All of the above. Clinical: careful dissection required to avoid vascular/nerve injury.
9) Surgical importance of clavipectoral fascia?
a) Defines axillary surgical plane
b) Stabilizes clavicle
c) Prevents scapular rotation
d) Guides deltoid function
Explanation: Clavipectoral fascia acts as an anatomical landmark for axillary surgeries. Correct answer: Defines axillary surgical plane. Clinical: helps surgeons avoid injury to axillary neurovascular structures.
10) Coracoclavicular ligament function is:
a) Stabilize acromioclavicular joint
b) Stabilize sternoclavicular joint
c) Prevent humeral displacement
d) Reinforce shoulder capsule
Explanation: Coracoclavicular ligament is the major stabilizer of acromioclavicular joint. Correct answer: Stabilize acromioclavicular joint. Clinical: rupture causes “shoulder separation” injury.
Keyword Definitions
• Brachial plexus – A network of nerves formed by ventral rami of C5–T1, supplying upper limb.
• Infraclavicular branches – Nerves arising below clavicle from cords of brachial plexus.
• Supraclavicular branches – Nerves arising above clavicle, mainly from roots and trunks.
• Ulnar nerve – Terminal branch of medial cord; motor to intrinsic hand muscles and sensory to medial hand.
• Long thoracic nerve – Supraclavicular branch from roots (C5–C7); supplies serratus anterior.
• Axillary nerve – Terminal branch of posterior cord; supplies deltoid and teres minor.
• Thoracodorsal nerve – Branch of posterior cord; supplies latissimus dorsi.
• Cords of brachial plexus – Named medial, lateral, posterior according to relation with axillary artery.
• Clinical correlation – Injury to long thoracic nerve causes winging of scapula.
• Fascial compartments – Axilla contains cords of plexus, vessels, and lymph nodes surrounded by sheath.
Chapter: Anatomy / Upper Limb
Topic: Brachial Plexus
Subtopic: Infraclavicular vs Supraclavicular Branches
Lead Question – 2013
All are infraclavicular branches of brachial plexus except?
a) Ulnar nerve
b) Long thoracic nerve
c) Axillary nerve
d) Thoracodorsal nerve
Explanation: Infraclavicular branches arise from cords of brachial plexus. Ulnar, axillary, and thoracodorsal nerves are infraclavicular. Long thoracic nerve arises from roots above the clavicle, hence it is supraclavicular. Correct answer: Long thoracic nerve. Clinically, injury to this nerve produces winged scapula due to serratus anterior paralysis.
Guessed Questions for NEET PG
1) Which nerve is injured in winged scapula?
a) Axillary nerve
b) Long thoracic nerve
c) Thoracodorsal nerve
d) Dorsal scapular nerve
Explanation: Winged scapula occurs due to paralysis of serratus anterior muscle from long thoracic nerve injury. Correct answer: Long thoracic nerve. Clinical: commonly injured in axillary dissections or trauma to lateral thoracic wall.
2) Axillary nerve supplies which muscle?
a) Latissimus dorsi
b) Teres major
c) Teres minor
d) Pectoralis minor
Explanation: Axillary nerve innervates deltoid and teres minor. Correct answer: Teres minor. Clinical: Injury causes inability to abduct shoulder beyond 15° and loss of sensation over deltoid patch.
3) Thoracodorsal nerve supplies:
a) Pectoralis major
b) Latissimus dorsi
c) Subscapularis
d) Serratus anterior
Explanation: Thoracodorsal nerve (middle subscapular nerve) arises from posterior cord and supplies latissimus dorsi. Correct answer: Latissimus dorsi. Clinical: important in flap surgeries like latissimus dorsi flap for reconstruction.
4) Ulnar nerve lesion at wrist causes:
a) Wrist drop
b) Claw hand
c) Ape thumb
d) Foot drop
Explanation: Ulnar nerve injury at wrist leads to claw hand due to loss of intrinsic hand muscles. Correct answer: Claw hand. Clinical: common in fractures of hook of hamate or lacerations.
5) Which is a supraclavicular branch of brachial plexus?
a) Musculocutaneous nerve
b) Long thoracic nerve
c) Median nerve
d) Ulnar nerve
Explanation: Long thoracic nerve arises from roots (C5–C7) above the clavicle, making it a supraclavicular branch. Correct answer: Long thoracic nerve. Clinical: vulnerable during axillary lymph node dissection.
6) Which cord gives rise to median nerve?
a) Lateral cord only
b) Medial cord only
c) Both medial and lateral cords
d) Posterior cord
Explanation: Median nerve arises from contributions of both medial and lateral cords. Correct answer: Both medial and lateral cords. Clinical: median nerve lesions cause loss of thumb opposition and ape thumb deformity.
7) Posterior cord of brachial plexus gives rise to:
a) Axillary and radial nerves
b) Ulnar and radial nerves
c) Median and ulnar nerves
d) Musculocutaneous and median nerves
Explanation: Posterior cord terminates as axillary and radial nerves. Correct answer: Axillary and radial nerves. Clinical: injuries affect shoulder abduction and wrist extension respectively.
8) Klumpke’s palsy involves which roots?
a) C5–C6
b) C7
c) C8–T1
d) C5–C7
Explanation: Klumpke’s palsy occurs due to injury to C8–T1 roots, affecting intrinsic hand muscles. Correct answer: C8–T1. Clinical: causes claw hand deformity and sensory loss in medial forearm and hand.
9) Erb’s palsy involves paralysis of:
a) Flexors of forearm
b) Extensors of wrist
c) Abductors and lateral rotators of shoulder
d) Intrinsic muscles of hand
Explanation: Erb’s palsy occurs due to C5–C6 root lesion, affecting deltoid, supraspinatus, infraspinatus, and biceps. Correct answer: Abductors and lateral rotators of shoulder. Clinical: arm hangs medially rotated, extended, pronated (“waiter’s tip”).
10) Which nerve accompanies posterior circumflex humeral artery?
a) Musculocutaneous nerve
b) Radial nerve
c) Axillary nerve
d) Median nerve
Explanation: Axillary nerve travels with posterior circumflex humeral artery through quadrangular space. Correct answer: Axillary nerve. Clinical: injured in surgical neck fractures of humerus.
Keyword Definitions
• Thoracodorsal nerve – Branch of posterior cord, supplies latissimus dorsi.
• Root value – Spinal nerves contributing fibers to a peripheral nerve.
• Brachial plexus – Formed by ventral rami of C5–T1, supplies upper limb.
• Latissimus dorsi – Muscle aiding extension, adduction, and medial rotation of humerus.
• Posterior cord – Division of brachial plexus formed by posterior divisions of all trunks.
• Axillary nerve – Terminal branch of posterior cord, innervates deltoid and teres minor.
• Long thoracic nerve – Arises from C5–C7 roots, supplies serratus anterior.
• Suprascapular nerve – Arises from upper trunk, supplies supraspinatus and infraspinatus.
• Clinical correlation – Injury to thoracodorsal nerve impairs arm adduction, weakens shoulder extension.
• Surgical relevance – Preserved during axillary clearance to maintain latissimus dorsi flap viability.
Chapter: Anatomy / Upper Limb
Topic: Brachial Plexus
Subtopic: Thoracodorsal Nerve
Lead Question – 2013
Root value of thoracodorsal nerve?
a) C5, C6, C7
b) C8, T1
c) C6, C7, C8
d) T1, T2
Explanation: Thoracodorsal nerve arises from the posterior cord of brachial plexus with root value C6, C7, and C8. It innervates latissimus dorsi, which is important in climbing and swimming. Correct answer: C6, C7, C8. Clinically preserved during axillary dissections to prevent functional loss of shoulder movements.
Guessed Questions for NEET PG
1) Nerve supply of latissimus dorsi is:
a) Thoracodorsal nerve
b) Dorsal scapular nerve
c) Axillary nerve
d) Long thoracic nerve
Explanation: Latissimus dorsi is supplied by the thoracodorsal nerve (C6–C8). Correct answer: Thoracodorsal nerve. Clinical: important for forceful adduction and extension of the arm, also preserved in reconstructive flap surgeries.
2) Root value of long thoracic nerve is:
a) C5–C7
b) C7–C9
c) C8–T1
d) C5–C6
Explanation: Long thoracic nerve arises from C5, C6, and C7 roots and supplies serratus anterior. Correct answer: C5–C7. Clinical: injury produces winged scapula due to paralysis of serratus anterior.
3) Which nerve is closely related to axillary lymph node dissection?
a) Thoracodorsal nerve
b) Median nerve
c) Ulnar nerve
d) Radial nerve
Explanation: Thoracodorsal nerve lies in the axilla and is at risk during axillary dissection. Correct answer: Thoracodorsal nerve. Clinical: its injury leads to weakness in shoulder extension and loss of latissimus dorsi flap viability.
4) Nerve injured in surgical neck fracture of humerus:
a) Axillary nerve
b) Radial nerve
c) Median nerve
d) Thoracodorsal nerve
Explanation: Axillary nerve winds around the surgical neck of humerus with posterior circumflex humeral artery. Correct answer: Axillary nerve. Clinical: injury causes inability to abduct shoulder beyond 15° and loss of sensation over deltoid patch.
5) Function of latissimus dorsi is:
a) Flexion and lateral rotation
b) Extension, adduction, medial rotation
c) Abduction and supination
d) Flexion and pronation
Explanation: Latissimus dorsi is a powerful extensor, adductor, and medial rotator of the arm. Correct answer: Extension, adduction, medial rotation. Clinical: active in climbing and swimming movements.
6) Root value of axillary nerve:
a) C5–C6
b) C7–C8
c) C8–T1
d) C5–C7
Explanation: Axillary nerve arises from posterior cord with root value C5 and C6. Correct answer: C5–C6. Clinical: injured in humeral fractures causing deltoid paralysis and sensory loss on upper arm.
7) Which nerve supplies serratus anterior?
a) Long thoracic nerve
b) Thoracodorsal nerve
c) Dorsal scapular nerve
d) Axillary nerve
Explanation: Serratus anterior is innervated by the long thoracic nerve (C5–C7). Correct answer: Long thoracic nerve. Clinical: injury produces winged scapula, especially during axillary lymph node dissection.
8) Root value of suprascapular nerve:
a) C5–C6
b) C6–C7
c) C8–T1
d) C5–C7
Explanation: Suprascapular nerve arises from the upper trunk of brachial plexus with root value C5–C6. Correct answer: C5–C6. Clinical: supplies supraspinatus and infraspinatus, important in shoulder abduction and external rotation.
9) Which nerve injury causes wrist drop?
a) Ulnar nerve
b) Median nerve
c) Radial nerve
d) Thoracodorsal nerve
Explanation: Radial nerve injury leads to paralysis of wrist extensors causing wrist drop. Correct answer: Radial nerve. Clinical: commonly seen in mid-shaft humerus fractures.
10) Klumpke’s palsy involves injury to:
a) Upper trunk (C5–C6)
b) Lower trunk (C8–T1)
c) Posterior cord
d) Medial cord
Explanation: Klumpke’s palsy occurs due to lower trunk (C8–T1) injury. Correct answer: Lower trunk (C8–T1). Clinical: causes claw hand deformity and weakness of intrinsic hand muscles.
Keyword Definitions
• Brachial plexus – Network of nerves formed by anterior rami of C5–T1 supplying upper limb.
• Radial nerve – Largest branch of brachial plexus, supplies extensor compartment of arm and forearm.
• Ulnar nerve – Arises from medial cord, supplies intrinsic hand muscles and medial forearm.
• Median nerve – Formed by medial and lateral cords, supplies anterior forearm and thenar muscles.
• Axillary nerve – Branch of posterior cord, supplies deltoid and teres minor.
• Posterior cord – Formed by posterior divisions of all trunks of brachial plexus.
• Musculocutaneous nerve – Arises from lateral cord, supplies anterior arm muscles.
• Clinical correlation – Radial nerve injury leads to wrist drop and sensory loss in dorsum of hand.
• Surgical relevance – Axillary dissection may endanger nerves such as thoracodorsal and long thoracic.
• Root value – Spinal segmental origin of a peripheral nerve, important in localization of lesions.
• Extensor compartment – Posterior arm and forearm muscles controlled by radial nerve.
Chapter: Anatomy / Upper Limb
Topic: Brachial Plexus
Subtopic: Radial Nerve
Lead Question – 2013
Largest branch of brachial plexus is
a) Ulnar
b) Median
c) Radial
d) Axillary
Explanation: The radial nerve is the largest branch of the brachial plexus. It arises from the posterior cord (C5–T1) and supplies the extensor compartments of the arm and forearm. Correct answer: Radial nerve. Clinically, its injury causes wrist drop and weak hand grip due to loss of extensors.
Guessed Questions for NEET PG
1) Root value of radial nerve is:
a) C5–C6
b) C5–T1
c) C7–T1
d) C6–C8
Explanation: Radial nerve is derived from the posterior cord of the brachial plexus with root values C5–T1. Correct answer: C5–T1. Clinically, knowledge of root value helps in diagnosing radiculopathies presenting with upper limb weakness.
2) Nerve injured in mid-shaft fracture of humerus:
a) Median
b) Ulnar
c) Radial
d) Axillary
Explanation: Radial nerve runs in the spiral groove of the humerus and is commonly injured in mid-shaft fractures. Correct answer: Radial nerve. This results in wrist drop due to paralysis of wrist extensors.
3) Which nerve supplies triceps brachii?
a) Axillary
b) Radial
c) Median
d) Musculocutaneous
Explanation: Triceps brachii, the main extensor of the elbow, is innervated by the radial nerve. Correct answer: Radial nerve. Clinical: injury above triceps branches causes loss of elbow extension along with wrist drop.
4) Nerve supply of supinator muscle is:
a) Median
b) Radial (deep branch)
c) Ulnar
d) Musculocutaneous
Explanation: The deep branch of the radial nerve, also called the posterior interosseous nerve, innervates the supinator muscle. Correct answer: Radial (deep branch). Clinical: weakness in supination if injured.
5) Wrist drop is due to injury of:
a) Median nerve
b) Ulnar nerve
c) Radial nerve
d) Musculocutaneous nerve
Explanation: Wrist drop occurs due to loss of extensor muscles supplied by the radial nerve. Correct answer: Radial nerve. Clinical: seen in humeral shaft fractures or compressive neuropathy ("Saturday night palsy").
6) Which nerve is closely related to spiral groove of humerus?
a) Axillary
b) Median
c) Radial
d) Ulnar
Explanation: The radial nerve courses through the spiral groove of the humerus. Correct answer: Radial nerve. Clinical: susceptible to injury in humeral shaft fractures leading to sensory and motor deficits.
7) Posterior interosseous nerve is a branch of:
a) Median
b) Ulnar
c) Radial
d) Axillary
Explanation: Posterior interosseous nerve is the terminal deep branch of radial nerve after passing through supinator. Correct answer: Radial nerve. Clinical: supplies most extensor muscles of forearm.
8) Which nerve supplies skin over dorsum of first web space?
a) Median
b) Ulnar
c) Radial
d) Musculocutaneous
Explanation: The dorsal digital branch of radial nerve supplies skin of first web space between thumb and index finger. Correct answer: Radial nerve. Clinical: sensory loss here confirms radial nerve lesion.
9) Nerve injured in improper use of crutches (“crutch palsy”):
a) Median
b) Radial
c) Ulnar
d) Axillary
Explanation: Radial nerve injury occurs in axilla due to compression from crutches or prolonged pressure. Correct answer: Radial nerve. Clinical: causes wrist drop and weakness of grip.
10) Which nerve is tested by extension of wrist against resistance?
a) Median
b) Ulnar
c) Radial
d) Axillary
Explanation: Radial nerve integrity is tested by checking wrist extension against resistance. Correct answer: Radial nerve. Clinical: inability indicates lesion of radial nerve or its branches.
Keyword Definitions
• Radial nerve – Largest branch of brachial plexus, supplies extensors of arm and forearm.
• Posterior interosseous nerve – Deep terminal branch of radial nerve, supplies finger extensors.
• Median nerve – Supplies most anterior forearm muscles and thenar muscles.
• Ulnar nerve – Supplies intrinsic hand muscles and medial forearm muscles.
• Wrist drop – Inability to extend wrist due to radial nerve injury.
• Spiral groove – Location of radial nerve on humerus, commonly injured in fractures.
• Crutch palsy – Radial nerve injury due to axillary compression from crutches.
• Dorsal digital branch – Radial nerve branch supplying skin over first web space.
• Clinical localization – Identifying nerve injuries based on motor and sensory deficits.
• Supinator canal – Site where posterior interosseous nerve may be compressed.
• Extensor compartment – Posterior muscles of forearm responsible for finger/wrist extension.
Chapter: Anatomy / Upper Limb
Topic: Brachial Plexus
Subtopic: Posterior Interosseous Nerve
Lead Question – 2013
A person had injury to right upper limb he is not able to extend fingers but able to extend wrist and elbow. Nerve injured is ?
a) Radial
b) Median
c) Ulnar
d) Posterior interosseous
Explanation: Finger extension is controlled by posterior interosseous nerve, a branch of radial nerve. Wrist and elbow extension are preserved because proximal radial nerve branches are intact. Correct answer: Posterior interosseous nerve. Clinical: injury produces finger drop without wrist drop.
Guessed Questions for NEET PG
1) Which nerve is injured in humeral shaft fracture leading to wrist drop?
a) Median
b) Radial
c) Ulnar
d) Axillary
Explanation: Radial nerve travels in the spiral groove of humerus and is vulnerable in shaft fractures. Injury leads to wrist drop and sensory loss in dorsum of hand. Correct answer: Radial nerve. Clinical: triceps often spared due to proximal innervation.
2) A patient with wrist extension preserved but inability to extend thumb likely has lesion of:
a) Median nerve
b) Radial nerve
c) Posterior interosseous nerve
d) Ulnar nerve
Explanation: Posterior interosseous nerve specifically supplies thumb extensors. Wrist extension is preserved via intact extensor carpi radialis longus. Correct answer: Posterior interosseous nerve. Clinical: selective finger drop is hallmark.
3) Inability to oppose thumb is due to injury of:
a) Ulnar nerve
b) Median nerve
c) Radial nerve
d) Musculocutaneous nerve
Explanation: Median nerve supplies thenar muscles including opponens pollicis. Its injury prevents thumb opposition. Correct answer: Median nerve. Clinical: seen in carpal tunnel syndrome or wrist lacerations.
4) Which nerve is injured in “Saturday night palsy”?
a) Radial
b) Ulnar
c) Median
d) Axillary
Explanation: Prolonged pressure in axilla compresses radial nerve, leading to wrist drop. Correct answer: Radial nerve. Clinical: common in unconscious patients with arm hanging over chair.
5) Loss of sensation in first dorsal web space occurs in:
a) Median nerve lesion
b) Ulnar nerve lesion
c) Radial nerve lesion
d) Axillary nerve lesion
Explanation: The radial nerve supplies skin over dorsum of first web space. Correct answer: Radial nerve. Clinical: this sensory loss confirms radial nerve lesion.
6) Which nerve passes through supinator canal and may be compressed there?
a) Ulnar
b) Median
c) Posterior interosseous
d) Axillary
Explanation: Posterior interosseous nerve passes through supinator canal (Arcade of Frohse) where entrapment can occur. Correct answer: Posterior interosseous nerve. Clinical: presents with finger drop but preserved wrist extension.
7) A patient cannot extend elbow. The nerve involved is:
a) Median
b) Radial
c) Ulnar
d) Musculocutaneous
Explanation: Radial nerve supplies triceps brachii responsible for elbow extension. Injury proximal to triceps branches leads to loss of elbow extension. Correct answer: Radial nerve.
8) Inability to adduct fingers is due to lesion of:
a) Median nerve
b) Ulnar nerve
c) Radial nerve
d) Axillary nerve
Explanation: Ulnar nerve supplies interossei muscles responsible for finger adduction and abduction. Correct answer: Ulnar nerve. Clinical: test by asking patient to hold a card between fingers (card test).
9) Which nerve is commonly injured during axillary lymph node dissection?
a) Long thoracic
b) Radial
c) Axillary
d) Median
Explanation: Long thoracic and thoracodorsal nerves are at risk, but not radial. Correct answer: Long thoracic nerve. Clinical: its injury leads to winging of scapula due to serratus anterior paralysis.
10) A patient with inability to pronate forearm likely has injury of:
a) Radial nerve
b) Median nerve
c) Ulnar nerve
d) Axillary nerve
Explanation: Median nerve supplies pronator teres and pronator quadratus. Injury causes loss of pronation. Correct answer: Median nerve. Clinical: pronation deficit helps localize lesion.
Keyword Definitions
• Radial nerve – Largest branch of brachial plexus, supplies posterior compartment of arm and forearm.
• Spiral groove – Groove on humerus where radial nerve travels, common injury site in fractures.
• Triceps brachii – Muscle with three heads (long, lateral, medial), main extensor of elbow.
• Extensor carpi radialis longus (ECRL) – Radial nerve branch above spiral groove, extends wrist.
• Wrist drop – Inability to extend wrist due to radial nerve lesion.
• Posterior interosseous nerve – Deep radial branch, supplies finger extensors.
• Saturday night palsy – Radial nerve compression in axilla leading to wrist drop.
• Humeral shaft fracture – Common cause of radial nerve injury at spiral groove.
• Supinator canal – Site of posterior interosseous nerve entrapment.
• Clinical localization – Identifying nerve injury by selective motor/sensory loss.
• Dorsal web space – Sensory area supplied by superficial radial nerve.
Chapter: Anatomy / Upper Limb
Topic: Brachial Plexus
Subtopic: Radial Nerve at Spiral Groove
Lead Question – 2013
Which muscle will be paralyzed when radial nerve is injured in just below the spiral groove ?
a) Lateral head of triceps
b) Medial head of triceps
c) Long head of triceps
d) ECRL
Explanation: Radial nerve gives branches to triceps before entering spiral groove, sparing it in distal lesions. ECRL is also supplied above the groove. Injury just below spiral groove paralyzes medial head of triceps. Correct answer: Medial head of triceps. Clinical: elbow extension weak but not absent.
Guessed Questions for NEET PG
1) In a mid-shaft humeral fracture, which motor deficit is most expected?
a) Loss of elbow extension
b) Wrist drop
c) Loss of pronation
d) Finger flexion weakness
Explanation: Radial nerve in spiral groove is injured, sparing triceps but affecting wrist/finger extensors. This causes wrist drop while elbow extension remains intact. Correct answer: Wrist drop. Clinical: selective extensor weakness helps localize lesion.
2) A patient with radial nerve injury in axilla will present with:
a) Wrist drop only
b) Elbow and wrist extension loss
c) Only sensory loss
d) Finger abduction loss
Explanation: Axillary radial nerve lesion affects triceps, wrist extensors, and sensory branches. This produces loss of elbow and wrist extension with sensory loss. Correct answer: Elbow and wrist extension loss. Clinical: classic in crutch palsy.
3) Which muscle is spared in radial nerve injury at spiral groove?
a) Extensor digitorum
b) Extensor carpi radialis longus
c) Extensor pollicis longus
d) Extensor indicis
Explanation: ECRL is supplied before spiral groove. Thus, wrist extension is weak but not lost. Correct answer: Extensor carpi radialis longus. Clinical: partial wrist drop seen instead of complete.
4) Loss of thumb extension is seen in injury to:
a) Median nerve
b) Ulnar nerve
c) Posterior interosseous nerve
d) Musculocutaneous nerve
Explanation: Posterior interosseous nerve supplies extensor pollicis longus and brevis. Its injury causes inability to extend thumb. Correct answer: Posterior interosseous nerve. Clinical: selective thumb drop without wrist involvement.
5) A patient cannot adduct fingers but wrist extension is normal. Likely nerve injured?
a) Radial
b) Median
c) Ulnar
d) Axillary
Explanation: Ulnar nerve supplies interossei for finger adduction. Radial nerve intact preserves wrist extension. Correct answer: Ulnar nerve. Clinical: card test positive.
6) Injury to radial nerve just above wrist affects:
a) Motor only
b) Sensory only
c) Both motor and sensory
d) Neither
Explanation: At wrist, radial nerve is superficial and purely sensory. Injury here causes sensory loss in dorsum of first web space. Correct answer: Sensory only. Clinical: no motor deficit seen.
7) Which nerve is tested by sensation over dorsal first web space?
a) Median
b) Ulnar
c) Radial
d) Musculocutaneous
Explanation: Radial nerve superficial branch supplies skin of first web space dorsally. Correct answer: Radial nerve. Clinical: useful in localizing high radial lesions.
8) Which nerve injury produces “claw hand”?
a) Median
b) Ulnar
c) Radial
d) Axillary
Explanation: Ulnar nerve injury at wrist causes paralysis of medial lumbricals leading to claw hand deformity. Correct answer: Ulnar nerve. Clinical: worsens with distal lesions.
9) Inability to supinate forearm after fracture of proximal radius is due to injury of:
a) Median
b) Radial
c) Musculocutaneous
d) Ulnar
Explanation: Supinator is innervated by posterior interosseous nerve, branch of radial. Injury near proximal radius affects supination. Correct answer: Radial nerve. Clinical: partial supination possible via biceps if intact.
10) A patient develops wrist drop after sleeping with arm compressed over chair. This condition is called:
a) Crutch palsy
b) Saturday night palsy
c) Honeymoon palsy
d) Arcade syndrome
Explanation: Compression of radial nerve in axilla during deep sleep causes Saturday night palsy. Correct answer: Saturday night palsy. Clinical: wrist drop with sensory loss over dorsum hand.
Keyword Definitions
• Ulnar nerve – Terminal branch of medial cord of brachial plexus, supplies intrinsic hand muscles and some forearm flexors.
• Flexor carpi ulnaris (FCU) – Forearm muscle, flexes and adducts wrist, supplied by ulnar nerve.
• Flexor digitorum profundus (FDP) – Deep flexor of fingers, medial half supplied by ulnar nerve, lateral half by median nerve.
• Forearm flexors – Muscles anterior to radius/ulna, flex wrist and fingers.
• Medial cord – Branch of brachial plexus giving rise to ulnar nerve.
• Cubital tunnel – Anatomical passage for ulnar nerve at elbow, common entrapment site.
• Claw hand – Deformity caused by ulnar nerve injury, hyperextension at MCP, flexion at IP joints.
• Guyon’s canal – Ulnar nerve compression site at wrist.
• Sensory supply – Ulnar nerve supplies medial 1½ fingers and corresponding palm/dorsum.
• Motor supply – Ulnar nerve supplies FCU, medial FDP, and most intrinsic hand muscles.
• Clinical localization – Identifying site of nerve injury based on selective muscle/sensory involvement.
Chapter: Anatomy / Upper Limb
Topic: Brachial Plexus
Subtopic: Ulnar Nerve in Arm and Forearm
Lead Question – 2013
In arm ulnar nerve gives muscular branch to which muscle ?
a) FCU
b) FDP
c) Both
d) None
Explanation: In the arm, the ulnar nerve does not supply any muscle. It simply travels down medially without branches. FCU and FDP receive branches in the forearm, not arm. Correct answer: None. Clinical: important in localizing lesions since proximal arm injuries do not affect muscle action directly.
Guessed Questions for NEET PG
1) Which muscle is supplied by ulnar nerve in the forearm?
a) Pronator teres
b) Flexor carpi ulnaris
c) Flexor pollicis longus
d) Palmaris longus
Explanation: Ulnar nerve supplies FCU and medial half of FDP in the forearm. Flexor carpi ulnaris is a key muscle supplied by it. Correct answer: Flexor carpi ulnaris. Clinical: tested by resisted wrist flexion and adduction.
2) A patient with ulnar nerve lesion at elbow will have weakness of:
a) Pronation
b) Wrist flexion and adduction
c) Wrist extension
d) Supination
Explanation: Elbow lesion of ulnar nerve affects FCU and medial FDP. This weakens wrist flexion/adduction and finger flexion. Correct answer: Wrist flexion and adduction. Clinical: combined with sensory loss over medial hand.
3) Which deformity is caused by distal ulnar nerve lesion at wrist?
a) Wrist drop
b) Claw hand
c) Ape thumb
d) Benediction sign
Explanation: Distal ulnar nerve lesion causes paralysis of lumbricals/interossei leading to claw hand deformity. Correct answer: Claw hand. Clinical: more severe when lesion is distal because FDP is spared.
4) Which nerve is compressed in Guyon’s canal syndrome?
a) Radial
b) Median
c) Ulnar
d) Musculocutaneous
Explanation: Ulnar nerve passes through Guyon’s canal near wrist. Compression here produces sensory and motor loss in ulnar distribution without affecting forearm muscles. Correct answer: Ulnar nerve. Clinical: common in cyclists ("handlebar palsy").
5) Which intrinsic hand muscle is not supplied by ulnar nerve?
a) Adductor pollicis
b) First dorsal interosseous
c) Lateral two lumbricals
d) Palmar interossei
Explanation: Median nerve supplies lateral two lumbricals and thenar muscles (except adductor pollicis). Ulnar supplies all others. Correct answer: Lateral two lumbricals. Clinical: important for fine finger movements.
6) Injury to ulnar nerve at elbow spares which muscle?
a) FCU
b) FDP (medial half)
c) FDP (lateral half)
d) Palmar interossei
Explanation: Lateral half of FDP is supplied by median nerve, not ulnar nerve. Hence spared in elbow lesion. Correct answer: FDP (lateral half). Clinical: helps differentiate median vs ulnar nerve contributions.
7) Sensory supply of ulnar nerve includes:
a) Lateral 3½ fingers
b) Medial 1½ fingers
c) Entire palm
d) Thenar eminence
Explanation: Ulnar nerve supplies skin of medial 1½ fingers and adjacent palm/dorsum. Correct answer: Medial 1½ fingers. Clinical: loss of sensation here is diagnostic.
8) Froment’s sign is positive in lesion of:
a) Radial nerve
b) Median nerve
c) Ulnar nerve
d) Axillary nerve
Explanation: Froment’s sign indicates weakness of adductor pollicis supplied by ulnar nerve. Thumb flexion occurs due to compensation by flexor pollicis longus. Correct answer: Ulnar nerve. Clinical: classic bedside test.
9) A patient with difficulty in finger abduction most likely has injury to:
a) Median nerve
b) Ulnar nerve
c) Radial nerve
d) Musculocutaneous nerve
Explanation: Interossei supplied by ulnar nerve abduct/adduct fingers. Injury impairs abduction. Correct answer: Ulnar nerve. Clinical: seen in claw hand cases.
10) Which test checks for integrity of ulnar nerve?
a) Phalen’s test
b) Card test
c) Tinel’s sign
d) O’Brien’s test
Explanation: Card test involves holding paper between fingers using interossei. Ulnar nerve lesion causes inability to hold paper. Correct answer: Card test. Clinical: simple bedside diagnostic tool.
Keyword Definitions
• Humerus – Long bone of upper limb extending from shoulder to elbow.
• Ossification center – Site where bone formation begins during development.
• Primary center – First ossification site, usually diaphysis of long bone.
• Secondary center – Ossification sites in epiphysis, appear later.
• Distal humerus – Lower end of humerus forming part of elbow joint.
• Capitulum – Lateral articular surface of distal humerus, articulates with radius.
• Trochlea – Medial articular surface of distal humerus, articulates with ulna.
• Epicondyle – Bony prominence above condyles for muscle attachment.
• Epiphysis – End part of long bone formed from secondary centers.
• Physis – Growth plate between diaphysis and epiphysis.
• Clinical relevance – Helps in diagnosing pediatric fractures and growth disturbances.
Chapter: Anatomy / Upper Limb
Topic: Osteology of Humerus
Subtopic: Ossification Centers of Distal Humerus
Lead Question – 2013
Distal end of humerus develops from how many centres ?
a) 2
b) 5
c) 3
d) 4
Explanation: The distal end of humerus has multiple secondary ossification centers – capitulum, trochlea, lateral epicondyle, medial epicondyle. Together, there are 4 centers. Correct answer: 4. Clinical: knowledge of ossification sequence (CRITOE rule) is important in interpreting pediatric elbow X-rays.
Guessed Questions for NEET PG
1) First ossification center to appear at distal humerus?
a) Capitulum
b) Trochlea
c) Medial epicondyle
d) Lateral epicondyle
Explanation: The capitulum is the first secondary ossification center to appear, around 1 year of age. Others follow in a predictable CRITOE sequence. Correct answer: Capitulum. Clinical: helps differentiate normal ossification centers from fracture fragments in pediatric radiographs.
2) Medial epicondyle ossification center appears at which age?
a) 2 years
b) 5 years
c) 7 years
d) 9 years
Explanation: The medial epicondyle ossification center appears around 5 years of age and fuses late, around puberty. Correct answer: 5 years. Clinical: it is the most common site of avulsion fracture in children due to throwing injuries.
3) Which ossification center fuses last in distal humerus?
a) Capitulum
b) Trochlea
c) Medial epicondyle
d) Lateral epicondyle
Explanation: Medial epicondyle is the last to fuse, around 18–20 years. Correct answer: Medial epicondyle. Clinical: helps identify skeletal maturity and growth potential in radiographs.
4) Sequence of ossification centers in elbow joint is remembered by acronym:
a) CRITOE
b) SALTER
c) ABCDEF
d) PRISME
Explanation: CRITOE – Capitulum, Radial head, Internal epicondyle (medial), Trochlea, Olecranon, External epicondyle (lateral). Correct answer: CRITOE. Clinical: used to read pediatric elbow X-rays and prevent misdiagnosis of normal centers as fractures.
5) At what age does trochlea ossification center appear?
a) 2 years
b) 7 years
c) 9 years
d) 12 years
Explanation: Trochlea ossification center appears around 9 years. Correct answer: 9 years. Clinical: irregular ossification pattern here can mimic fracture in children, so proper sequence knowledge is vital.
6) Failure of medial epicondyle fusion leads to:
a) Cubitus varus
b) Cubitus valgus
c) Recurvatum
d) Radial head dislocation
Explanation: Nonunion of medial epicondyle can cause valgus deformity due to loss of medial support. Correct answer: Cubitus valgus. Clinical: may lead to tardy ulnar nerve palsy in adults.
7) Which nerve is most endangered in medial epicondyle fractures?
a) Radial
b) Median
c) Ulnar
d) Musculocutaneous
Explanation: Ulnar nerve runs in groove behind medial epicondyle, making it vulnerable in avulsion fractures. Correct answer: Ulnar nerve. Clinical: may present with tingling in medial 1½ fingers.
8) In children, supracondylar fracture of humerus occurs commonly due to:
a) Direct trauma
b) Fall on flexed elbow
c) Fall on outstretched hand
d) Rotational injury
Explanation: Supracondylar fractures are common pediatric injuries due to fall on outstretched hand, leading to distal humerus fracture above condyles. Correct answer: Fall on outstretched hand. Clinical: may damage brachial artery and median nerve.
9) Which structure is at risk in supracondylar fracture of humerus?
a) Ulnar nerve
b) Radial artery
c) Brachial artery
d) Axillary nerve
Explanation: The brachial artery is closely related anteriorly and is most commonly injured in supracondylar fractures. Correct answer: Brachial artery. Clinical: leads to Volkmann’s ischemic contracture if untreated.
10) A 7-year-old presents with elbow swelling. X-ray shows separate ossification center at medial side. Most likely structure?
a) Capitulum
b) Trochlea
c) Medial epicondyle
d) Olecranon
Explanation: At 7 years, medial epicondyle ossification center is visible. Correct answer: Medial epicondyle. Clinical: distinguishing this from fracture fragment is crucial in pediatric practice.
Keyword Definitions
• Bursa – Fluid-filled sac reducing friction between tendon and bone.
• Synovial sheath – Tubular bursa surrounding a tendon for smooth gliding.
• Radial bursa – Synovial sheath enclosing flexor pollicis longus tendon.
• Ulnar bursa – Common flexor sheath for FDP and FDS tendons.
• Flexor pollicis longus (FPL) – Muscle flexing thumb distal phalanx.
• Flexor digitorum profundus (FDP) – Muscle flexing distal phalanges of fingers.
• Flexor digitorum superficialis (FDS) – Muscle flexing middle phalanges.
• Flexor carpi radialis (FCR) – Wrist flexor inserting into 2nd metacarpal.
• Thenar space – Potential space in palm communicating with radial bursa.
• Midpalmar space – Potential space in palm communicating with ulnar bursa.
• Clinical relevance – Infections of synovial sheaths may spread rapidly to palm and forearm.
Chapter: Anatomy / Upper Limb
Topic: Hand and Forearm Structures
Subtopic: Synovial Sheaths and Bursae of Hand
Lead Question – 2013
Radial bursa is the synovial sheath covering the tendon of ?
a) FDS
b) FDP
c) FPL
d) FCR
Explanation: The radial bursa is the synovial sheath of flexor pollicis longus (FPL) tendon. It extends from wrist into the thumb. Correct answer: FPL. Clinical: infection here (tenosynovitis) may spread into the forearm and cause “horseshoe abscess” by communicating with the ulnar bursa.
Guessed Questions for NEET PG
1) Ulnar bursa covers tendons of:
a) FPL
b) FDP and FDS
c) FCR
d) EPL
Explanation: Ulnar bursa is the common flexor sheath enclosing tendons of FDP and FDS to fingers. Correct answer: FDP and FDS. Clinical: infections here can spread into midpalmar space, causing swelling and impaired finger movements.
2) Horseshoe abscess occurs due to communication between:
a) Radial and ulnar bursa
b) Ulnar bursa and carpal tunnel
c) Radial bursa and midpalmar space
d) Thenar and hypothenar spaces
Explanation: Radial bursa of thumb communicates with ulnar bursa of little finger, producing a characteristic “horseshoe-shaped abscess.” Correct answer: Radial and ulnar bursa. Clinical: requires early drainage to prevent spread to forearm.
3) Infection of thumb flexor tendon sheath may spread into:
a) Thenar space
b) Midpalmar space
c) Parona’s space
d) Dorsum of hand
Explanation: FPL tendon sheath infection spreads through radial bursa into Parona’s space (forearm). Correct answer: Parona’s space. Clinical: severe swelling of forearm seen in advanced tenosynovitis.
4) Which tendon passes separately in its own sheath within carpal tunnel?
a) FPL
b) FDP
c) FDS
d) Palmaris longus
Explanation: FPL passes in its own synovial sheath (radial bursa) through the carpal tunnel. Correct answer: FPL. Clinical: inflammation here may cause isolated thumb pain in carpal tunnel syndrome.
5) Parona’s space is located:
a) Between palmar aponeurosis and flexor tendons
b) Between pronator quadratus and flexor tendons
c) In dorsal hand
d) In thenar eminence
Explanation: Parona’s space is between pronator quadratus and flexor tendons in distal forearm. Correct answer: Between pronator quadratus and flexor tendons. Clinical: serves as pathway for spread of infection from radial or ulnar bursa.
6) Which of the following muscles inserts into the distal phalanx of thumb?
a) FPL
b) FDS
c) FDP
d) EPL
Explanation: Flexor pollicis longus (FPL) inserts into the base of distal phalanx of thumb, flexing IP joint. Correct answer: FPL. Clinical: important in pinch grip strength, loss indicates anterior interosseous nerve palsy.
7) Ulnar bursa commonly extends up to which finger?
a) Index
b) Middle
c) Ring
d) Little
Explanation: The ulnar bursa extends into the little finger flexor sheath. Correct answer: Little finger. Clinical: explains why infections of little finger flexor sheath can spread to common flexor sheath and palm.
8) Which structure is enclosed within both radial bursa and carpal tunnel?
a) FCR
b) FPL
c) EPL
d) Lumbricals
Explanation: FPL tendon passes through carpal tunnel inside its radial bursa sheath. Correct answer: FPL. Clinical: tenosynovitis here may mimic carpal tunnel syndrome with isolated thumb symptoms.
9) A 25-year-old presents with swelling of thumb and little finger tendon sheaths with forearm spread. Most likely condition?
a) Thenar abscess
b) Midpalmar abscess
c) Horseshoe abscess
d) Carpal tunnel syndrome
Explanation: Simultaneous infection of radial and ulnar bursae produces characteristic horseshoe abscess. Correct answer: Horseshoe abscess. Clinical: requires surgical drainage through palmar incisions.
10) Which flexor tendon does not pass through the carpal tunnel?
a) FCR
b) FDP
c) FDS
d) FPL
Explanation: Flexor carpi radialis (FCR) passes in its own canal, not inside carpal tunnel. Correct answer: FCR. Clinical: helps distinguish isolated FCR tenosynovitis from carpal tunnel pathologies.
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.