Upper Limb Practice Questions

Q: Which of the following structures is present in the posterior axillary wall?

Subscapular artery. ### Explanation The **axilla** is a pyramidal space between the upper limb and the thorax. Understanding its boundaries is high-yield for NEET-PG. **1. Why the Subscapular Artery is Correct:** The **posterior wall** of the axilla is formed by the Subscapularis (superiorly), Teres major, and Latissimus dorsi (inferiorly). The **Subscapular artery**, the largest branch of the third part of the axillary artery, descends along the lower border of the subscapularis muscle. Therefore, it lies directly on the posterior axillary wall before dividing into the circumflex scapular and thoracodorsal arteries. **2. Analysis of Incorrect Options:** * **Thoracodorsal artery (Option A):** While it is a branch of the subscapular artery, it typically enters the substance of the Latissimus dorsi [1]. In standard anatomical descriptions of the axillary walls, the parent **Subscapular artery** is the primary landmark associated with the posterior wall. * **Long thoracic nerve (Option B):** This nerve (C5-C7) descends on the external surface of the Serratus anterior muscle, which forms the **medial wall** of the axilla. * **Axillary artery (Option C):** The axillary artery and the cords of the brachial plexus are contained within the **axillary sheath**, which constitutes the **contents** of the axilla, rather than forming its walls. **3. Clinical Pearls & High-Yield Facts:** * **Medial Wall:** Serratus anterior and upper 4-5 ribs. * **Lateral Wall:** Bicipital groove of the humerus (very narrow). * **Anterior Wall:** Pectoralis major, Pectoralis minor, and Clavipectoral fascia. * **Nerve to Latissimus Dorsi (Thoracodorsal nerve):** Also lies on the posterior wall and is at risk during axillary lymph node dissection [1]. It crosses the axilla to reach the medial surface of the latissimus dorsi. * **Apex of Axilla:** Also known as the *cervico-axillary canal*, bounded by the clavicle, first rib, and upper border of the scapula.

Q: Which of the following is NOT typically seen in carpal tunnel syndrome?

Ulnar nerve involvement. **Explanation:** **Carpal Tunnel Syndrome (CTS)** is the most common entrapment neuropathy, caused by the compression of the **median nerve** as it passes through the carpal tunnel beneath the flexor retinaculum [2]. **1. Why Ulnar Nerve Involvement is the Correct Answer:** The ulnar nerve does **not** pass through the carpal tunnel. Instead, it travels superficial to the flexor retinaculum through **Guyon’s canal** (ulnar canal) [2]. Therefore, compression within the carpal tunnel typically spares the ulnar nerve. Clinical symptoms of CTS are localized to the median nerve distribution (lateral 3.5 fingers) [2]. **2. Analysis of Incorrect Options:** * **Median Nerve Compression (A):** This is the hallmark of CTS. The nerve is squeezed against the rigid walls of the tunnel, leading to paresthesia and thenar atrophy [1]. * **FPL (C) and FDP (D) Tendon Issues:** The carpal tunnel contains **10 structures**: the median nerve, the tendon of Flexor Pollicis Longus (1), the four tendons of Flexor Digitorum Superficialis (4), and the four tendons of Flexor Digitorum Profundus (4) [1]. Inflammation or tenosynovitis of these tendons is a primary cause of increased pressure within the tunnel, leading to nerve compression. **High-Yield Clinical Pearls for NEET-PG:** * **Sensory Sparing:** The **palmar cutaneous branch** of the median nerve arises proximal to the carpal tunnel; thus, sensation over the lateral palm is usually **preserved** in CTS [1], [2]. * **Tests:** Phalen’s test (forced flexion) and Tinel’s sign (percussion over the nerve) are classic diagnostic maneuvers. * **Muscle Involvement:** "LOAF" muscles (Lateral two lumbricals, Opponens pollicis, Abductor pollicis brevis, Flexor pollicis brevis) are affected. * **Most Common Cause:** Idiopathic; however, it is associated with pregnancy, hypothyroidism, diabetes, and rheumatoid arthritis.

Q: The pisiform bone articulates with which of the following carpal bones?

Triquetral. The **pisiform** is a small, pea-shaped sesamoid bone located in the proximal row of the carpus. It is unique because it is embedded within the tendon of the **flexor carpi ulnaris (FCU)** muscle. **1. Why Triquetral is correct:** The pisiform bone has only one articular facet, located on its posterior surface. This facet articulates exclusively with the **anterior (palmar) surface of the triquetral bone**, forming the pisotriquetral joint. Unlike other carpal bones, the pisiform does not participate in the radiocarpal (wrist) joint or the midcarpal joint. **2. Why other options are incorrect:** * **Lunate:** Located lateral to the triquetral in the proximal row; it articulates with the radius, scaphoid, triquetral, and capitate, but not the pisiform. * **Scaphoid:** The most lateral bone of the proximal row [1]; it articulates with the radius, lunate, trapezium, trapezoid, and capitate. * **Trapezoid:** A bone of the distal row; it articulates with the scaphoid, trapezium, capitate, and the second metacarpal. **High-Yield Clinical Pearls for NEET-PG:** * **Sesamoid Nature:** The pisiform is the only carpal bone that is a sesamoid bone (developed in the FCU tendon). * **Ossification:** It is the **last** carpal bone to ossify (usually between ages 9–12 years). * **Guyon’s Canal:** The pisiform forms the medial boundary of the ulnar canal (Guyon’s canal), making it a key landmark for identifying the ulnar nerve and artery at the wrist [1]. * **Palpation:** It is easily felt on the ulnar side of the distal wrist crease and moves slightly when the FCU is relaxed.

Q: Klumpke's paralysis results from a lesion of which part of the brachial plexus?

Lower brachial plexus injury. **Explanation:** **Klumpke’s Paralysis** is a clinical condition resulting from a lesion of the **lower trunk of the brachial plexus**, specifically involving the **C8 and T1 nerve roots**. 1. **Why Option B is Correct:** The lower brachial plexus (C8-T1) primarily supplies the intrinsic muscles of the hand (via the ulnar and median nerves). Injury typically occurs due to **hyperabduction of the arm** (e.g., clutching an object while falling from a height or a breech delivery). The hallmark clinical feature is **"Claw Hand"** (total clawing) due to the paralysis of lumbricals and interossei, which normally flex the MCP joints and extend the IP joints. 2. **Why Other Options are Incorrect:** * **Option A:** Upper brachial plexus injury (C5-C6) leads to **Erb’s Palsy**, characterized by the "Policeman’s tip" or "Waiter's tip" deformity. * **Option B:** Radial nerve injury typically results in **Wrist Drop**, not the global intrinsic muscle loss seen in Klumpke’s. * **Option D:** C5, C6, and C7 are associated with the upper and middle trunks. Klumpke’s specifically spares these and targets the lowermost roots. **High-Yield Clinical Pearls for NEET-PG:** * **Horner’s Syndrome:** Often associated with Klumpke’s paralysis because the **T1 root** carries sympathetic fibers to the face (presenting as miosis, ptosis, and anhidrosis). * **Mechanism of Injury:** Upward traction on the arm (Klumpke's) vs. Downward traction on the shoulder (Erb's). * **Muscle Involvement:** The most affected muscles are the **intrinsic muscles of the hand** and the long flexors of the fingers.

Q: Which statement regarding the anatomical spaces of the hand is true?

The thenar space lies lateral to the 3rd metacarpal.. **Explanation:** The deep fascial spaces of the palm are potential spaces filled with loose connective tissue, clinically significant for the localization and spread of infections [1]. **1. Why Option A is Correct:** The **thenar space** is a triangular space located deep to the thenar muscles. Its medial boundary is the **lateral palmar septum**, which is attached to the **3rd metacarpal bone**. Therefore, the thenar space lies lateral to the 3rd metacarpal, between it and the thenar eminence [1]. **2. Analysis of Incorrect Options:** * **Option B:** The **hypothenar space** is contained within the hypothenar compartment, bounded by the medial palmar septum (attached to the 5th metacarpal). It does not lie medial to the bone but rather surrounds the hypothenar muscles anterior/lateral to it. * **Option C:** While the **midpalmar space** is deep to the palmar aponeurosis, this is a vague description. Specifically, it lies deep to the **flexor tendons** and superficial to the interossei/metacarpals [1]. Option A is the more anatomically precise "textbook" definition regarding boundaries. * **Option D:** The **pulp spaces** (Whitman’s spaces) are located on the palmar aspect of the **distal phalanges** only, not the entire length of the fingers and thumb. They are partitioned by fibrous septa extending from the skin to the periosteum. **3. NEET-PG High-Yield Pearls:** * **Kanavel’s Signs:** Used to diagnose infectious tenosynovitis (e.g., symmetric swelling, finger in slight flexion, tenderness over sheath, pain on passive extension). * **Space of Parona:** A potential space in the distal forearm (deep to flexor tendons, superficial to pronator quadratus) where infections from the radial or ulnar bursae can track. * **Communication:** The midpalmar space often communicates with the forearm via the carpal tunnel.

Q: Which structure is referred to as a "dynamic stabilizer" of the shoulder joint?

Rotator cuff. **Explanation:** The shoulder (glenohumeral) joint is characterized by a high degree of mobility at the expense of stability, often compared to a "ball on a saucer." To maintain integrity, it relies on both static and dynamic stabilizers. **1. Why Rotator Cuff is Correct:** The **Rotator Cuff muscles** (Supraspinatus, Infraspinatus, Teres minor, and Subscapularis—mnemonic: **SITS**) are the primary **dynamic stabilizers**. They function by actively contracting to compress the humeral head into the shallow glenoid cavity throughout the range of motion. This mechanism, known as **"concavity-compression,"** prevents the humeral head from sliding out of the socket during movement. **2. Why Other Options are Incorrect:** * **Glenoid Labrum (B):** This is a fibrocartilaginous rim that deepens the glenoid cavity. It is a **static stabilizer**. * **Coracohumeral (C) and Glenohumeral Ligaments (D):** These are thickened parts of the joint capsule that provide stability only at the end-ranges of motion or when the muscles are relaxed. They are classified as **static stabilizers**. **3. NEET-PG High-Yield Pearls:** * **The "Fifth" Dynamic Stabilizer:** The **Long head of the Biceps brachii** is also considered a dynamic stabilizer as it prevents upward displacement of the humeral head. * **Weakest Point:** The rotator cuff is deficient **inferiorly**, which is why most shoulder dislocations occur in an antero-inferior direction. * **Rotator Interval:** A triangular space between the Supraspinatus and Subscapularis tendons; it is a common site for clinical pathology and surgical entry. * **Supraspinatus:** The most commonly injured rotator cuff muscle (often involved in impingement syndrome).

Q: Pointing index deformity is due to damage to which nerve?

Median. **Explanation:** The **Pointing Index Deformity** (also known as the **Ochsner’s Clench Sign**) occurs due to a lesion of the **Median Nerve**, typically at or above the elbow (e.g., supracondylar fracture of the humerus). **Why Median Nerve is correct:** When a patient with a high median nerve palsy attempts to make a fist, they are unable to flex the index and middle fingers. This happens because the median nerve supplies the **Flexor Digitorum Superficialis (FDS)** and the lateral half of the **Flexor Digitorum Profundus (FDP)** [1]. While the ring and little fingers can still flex (via the ulnar-supplied medial half of the FDP), the index finger remains straight/extended, resulting in a "pointing" appearance [1]. **Why other options are incorrect:** * **Ulnar Nerve:** Damage leads to "Ulnar Claw Hand" (hyperextension at MCP joints and flexion at IP joints of the ring and little fingers). It does not affect index finger flexion. Notably, the ulnar nerve innervates the FDP to the ring and small fingers [1]. * **Radial Nerve:** Damage leads to "Wrist Drop" due to paralysis of the extensors. Midshaft humeral fractures are commonly associated with this injury [1]. * **Axillary Nerve:** Damage leads to paralysis of the Deltoid and Teres Minor, resulting in loss of shoulder abduction and "Flat Shoulder" appearance. **Clinical Pearls for NEET-PG:** * **Hand of Benediction:** This is the same clinical presentation as Pointing Index, observed specifically when the patient **attempts to clench their fist**. * **Ape Thumb Deformity:** Also caused by Median nerve palsy, characterized by wasting of thenar muscles and inability to oppose the thumb. * **Kiloh-Nevin Syndrome:** Involvement of the **Anterior Interosseous Nerve** (branch of Median) where the patient cannot make an "OK" sign due to paralysis of Flexor Pollicis Longus and FDP to the index finger.

Question 1

Which of the following structures is present in the posterior axillary wall?

Accepted Answer

Subscapular artery

Answer

Thoracodorsal artery

Answer

Long thoracic nerve

Answer

Axillary artery

Question 2

Which of the following is NOT typically seen in carpal tunnel syndrome?

Accepted Answer

Ulnar nerve involvement

Answer

Median nerve compression

Answer

Flexor pollicis longus (FPL) tendon issues

Answer

Flexor digitorum profundus (FDP) tendon issues

Question 3

The pisiform bone articulates with which of the following carpal bones?

Accepted Answer

Triquetral

Answer

Lunate

Answer

Scaphoid

Answer

Trapezoid

Question 4

Klumpke's paralysis results from a lesion of which part of the brachial plexus?

Accepted Answer

Lower brachial plexus injury

Answer

Upper brachial plexus injury

Answer

Radial nerve injury

Answer

C5, C6, and C7 nerve roots injury

Question 5

When examining muscle function at the metacarpophalangeal (MP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints, what findings do you expect in the presence of radial nerve palsy?

Accepted Answer

Inability to extend the MP, PIP, and DIP joints

Answer

Inability to abduct the digits at the MP joint

Answer

Inability to adduct the digits at the MP joint

Answer

Inability to extend the MP joint only

Question 6

Which statement regarding the anatomical spaces of the hand is true?

Accepted Answer

The thenar space lies lateral to the 3rd metacarpal.

Answer

The hypothenar space lies medial to the 5th metacarpal.

Answer

The midpalmar space lies deep to the palmar aponeurosis.

Answer

The pulp spaces lie on the palmar aspect of the fingers and thumb.

Question 7

A 22-year-old man presents to the emergency department after sustaining trauma. He reports severe pain radiating across his back and down his left upper limb. He is supporting his left upper limb with his right, holding it close to his body, and any attempt to move the limb exacerbates the pain. A radiograph reveals a sagittal fracture through the spine of the left scapula that extends superiorly toward the suprascapular notch. Which nerve is most likely affected?

Accepted Answer

Suprascapular nerve

Answer

Thoracodorsal nerve

Answer

Axillary nerve

Answer

Subscapular nerve

Question 8

A patient presented with inability to flex the distal interphalangeal joints of the fourth and fifth fingers and is unable to hold a card between his fingers. Fracture at which of the following sites might have damaged the nerve, leading to this set of clinical features?

Accepted Answer

Hamate fracture

Answer

Scaphoid fracture

Answer

Colles' fracture

Answer

Bennett's fracture

Question 9

Which structure is referred to as a "dynamic stabilizer" of the shoulder joint?

Accepted Answer

Rotator cuff

Answer

Glenoid labrum

Answer

Coracohumeral ligament

Answer

Glenohumeral ligament

Question 10

Pointing index deformity is due to damage to which nerve?

Accepted Answer

Median

Answer

Ulnar

Answer

Radial

Answer

Axillary

Upper Limb — MCQs

Upper Limb — MCQs

On this page

Practice by Chapter

Want unlimited practice?