Upper Limb — MCQs

Upper Limb Indian Medical PG Practice Questions and MCQs

Question 761: Which artery passes through the anatomical snuffbox?

A. Radial artery (Correct Answer)
B. Brachial artery
C. Ulnar artery
D. Interosseus artery

Explanation: ***Radial artery*** - The **radial artery** is palpable within the **anatomical snuffbox**, as it courses over the scaphoid and trapezium bones towards the deep palmar arch. - This location is clinically significant for feeling the pulse and is vulnerable to injury, especially during **scaphoid fractures**. *Brachial artery* - The **brachial artery** is found in the **arm**, typically running in the cubital fossa, well proximal to the anatomical snuffbox. - It bifurcates into the radial and ulnar arteries at the level of the elbow, not within the wrist structures. *Ulnar artery* - The **ulnar artery** typically lies on the **medial side of the forearm** and wrist, contributing to the superficial palmar arch. - It does not pass through the anatomical snuffbox, which is located on the lateral aspect of the wrist. *Interosseus artery* - The **interosseus arteries** (anterior and posterior) run between the radius and ulna in the forearm, supplying muscles and bones. - These arteries are deep within the forearm compartments and do not traverse the superficial anatomical snuffbox at the wrist.

Question 762: Teres minor is supplied by

A. Suprascapular nerve
B. Lower subscapular nerve
C. Thoracodorsal nerve
D. Axillary nerve (Correct Answer)

Explanation: ***Axillary nerve*** - The **axillary nerve** (C5-C6) innervates both the **teres minor** and the **deltoid muscle**. - It arises from the posterior cord of the brachial plexus and traverses the quadrangular space. *Suprascapular nerve* - The **suprascapular nerve** (C5-C6) primarily supplies the **supraspinatus** and **infraspinatus** muscles. - It plays a crucial role in shoulder abduction and external rotation, but not directly in teres minor function. *Lower subscapular nerve* - The **lower subscapular nerve** (C5-C6) innervates the **subscapularis muscle** and **teres major**. - Teres major and teres minor are anatomically adjacent but have different innervations and functions. *Thoracodorsal nerve* - The **thoracodorsal nerve** (C6-C8) innervates the **latissimus dorsi muscle** [1]. - This nerve is distinct from those supplying the rotator cuff muscles, including teres minor.

Question 763: A person is not able to extend his metacarpophalangeal joint. Injury to which of the following nerve result in this?

A. Posterior Interosseous nerve injury (Correct Answer)
B. Radial nerve injury
C. Ulnar nerve injury
D. Median nerve injury

Explanation: Posterior Interosseous Nerve (PIN) injury - The Posterior Interosseous Nerve is the deep motor branch of the radial nerve that specifically innervates the extensor muscles of the fingers and thumb - These muscles include: Extensor Digitorum, Extensor Indicis, Extensor Digiti Minimi, Extensor Pollicis Longus and Brevis [1] - PIN injury causes inability to extend the MCP joints and interphalangeal joints of the fingers [1] - Wrist extension is preserved because the Extensor Carpi Radialis Longus (ECRL) and often ECRB are innervated by the radial nerve proper before it gives off the PIN [1] - This results in a characteristic finger drop without wrist drop Radial nerve injury - A high radial nerve injury (proximal, above the elbow) would cause both wrist drop AND finger extension loss - However, radial nerve injury at the spiral groove (most common site) typically spares the PIN or affects it less severely - The question asks specifically about isolated inability to extend MCP joints, which is the hallmark of PIN injury, not general radial nerve injury - Radial nerve proper gives branches to triceps, brachioradialis, and ECRL before dividing into PIN and superficial branch Ulnar nerve injury - The ulnar nerve innervates intrinsic hand muscles (interossei, lumbricals to digits 4-5, hypothenar muscles, adductor pollicis) [1] - Ulnar nerve injury causes claw hand deformity with MCP hyperextension (not loss of extension) and IP joint flexion - This is the opposite of what is described in the question Median nerve injury - The median nerve innervates the thenar muscles, lateral two lumbricals, and forearm flexors [1] - Median nerve injury causes ape hand deformity with loss of thumb opposition and flexion - It does not affect MCP joint extension, which is an extensor function

Question 764: Which muscle in the hand is unique for originating from the tendon of another muscle?

A. Palmaris longus
B. Lumbricals (Correct Answer)
C. Adductor pollicis
D. Flexor carpi radialis (FCR)

Explanation: ***Lumbricals*** - The **lumbrical muscles** in the hand are unique as they originate from the **tendons of the flexor digitorum profundus muscle** [1]. - This unusual origin allows them to act on both the metacarpophalangeal (MCP) joints (flexion) and the interphalangeal (IP) joints (extension) [1]. *Palmaris longus* - The **palmaris longus** muscle originates from the **medial epicondyle of the humerus**, not from the tendon of another muscle. - It inserts into the **palmar aponeurosis** and is absent in a significant portion of the population. *Flexor carpi radialis (FCR)* - The **flexor carpi radialis** originates from the **medial epicondyle of the humerus**. - It is a primary flexor and abductor of the wrist, inserting into the bases of the second and third metacarpal bones. *Adductor pollicis* - The **adductor pollicis** has two heads, transverse and oblique, both originating from the **carpal bones** and **metacarpals**, not from the tendon of another muscle. - Its main function is to adduct the thumb, pulling it towards the palm.

Question 765: 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. Median
B. Ulnar
C. Radial
D. Posterior interosseous (Correct Answer)

Explanation: ***Posterior interosseous*** - This nerve supplies the muscles responsible for **finger extension**, such as the **extensor digitorum**, **extensor indicis**, and **extensor digiti minimi**. - A lesion here would spare wrist and elbow extension because the nerves to the **extensor carpi radialis longus/brevis** and **triceps brachii** branch off the radial nerve proximal to the origin of the posterior interosseous nerve. *Radial* - A more proximal **radial nerve injury** would result in the inability to extend the wrist (leading to **wrist drop**), fingers, and thumb, which is not seen here as wrist extension is preserved. - It also innervates the **triceps brachii**, and a high radial nerve injury would affect elbow extension; this patient can extend their elbow. *Median* - The **median nerve** primarily innervates muscles responsible for **flexion** of the wrist and fingers, as well as **thumb opposition** and **pronation**. - Its injury would not directly lead to an inability to extend the fingers, but rather weakness in flexion and specific thumb movements. *Ulnar* - The **ulnar nerve** innervates most of the **intrinsic hand muscles** and the **flexor carpi ulnaris**, leading to weakness in finger abduction/adduction and flexion of the 4th and 5th digits. - It does not control finger extension, so an injury would not cause this specific deficit.

Question 766: Interosseous membrane of forearm is pierced by?

A. Brachial artery
B. Anterior interosseous artery (Correct Answer)
C. Posterior interosseous artery
D. Ulnar recurrent artery

Explanation: ***Anterior interosseous artery*** - The **anterior interosseous artery** pierces the **interosseous membrane** in the **distal forearm** (approximately 5 cm above the wrist) to anastomose with the **posterior interosseous artery** and contribute to the **palmar carpal arch**. - This artery arises from the **common interosseous artery**, a branch of the **ulnar artery**. - This is the **classically taught structure** that pierces the interosseous membrane and is the standard answer in examination contexts. *Brachial artery* - The **brachial artery** is the main artery of the arm and terminates in the **cubital fossa** by dividing into the **radial** and **ulnar arteries**. - It does not pierce the **interosseous membrane** of the forearm as it is located in the arm, not the forearm. *Posterior interosseous artery* - The **posterior interosseous artery** arises from the **common interosseous artery** and passes **posteriorly between the oblique cord and the upper border of the interosseous membrane** to enter the posterior compartment of the forearm. - While it may pierce the membrane distally to anastomose anteriorly, the **anterior interosseous artery** is the structure **classically described** as piercing the membrane in standard anatomical teaching and examination contexts. *Ulnar recurrent artery* - The **ulnar recurrent arteries** (anterior and posterior branches) arise from the **ulnar artery** near the **cubital fossa** and ascend to participate in the **anastomosis around the elbow joint**. - These arteries do not pierce the **interosseous membrane** of the forearm.

Question 767: All are supplied by the anterior interosseous nerve except which of the following?

A. Flexor carpi ulnaris (Correct Answer)
B. Pronator quadratus
C. Flexor digitorum profundus (lateral half)
D. Flexor pollicis longus

Explanation: ***Flexor carpi ulnaris*** - The **flexor carpi ulnaris** (FCU) is innervated by the **ulnar nerve**, not the anterior interosseous nerve [1]. - This is the correct answer as it is NOT supplied by the AIN. *Pronator quadratus* - The **pronator quadratus** IS supplied by the **anterior interosseous nerve**. - This deep muscle is responsible for **pronation of the forearm** and is one of the three muscles innervated by the AIN. *Flexor digitorum profundus (lateral half)* - The **lateral half of flexor digitorum profundus** (to index and middle fingers) IS supplied by the **anterior interosseous nerve**. - The medial half (to ring and little fingers) is supplied by the ulnar nerve. *Flexor pollicis longus* - The **flexor pollicis longus** (FPL) IS supplied by the **anterior interosseous nerve**. - This muscle is responsible for **flexion of the thumb's interphalangeal joint** and is one of the three muscles innervated by the AIN.

Question 768: Which muscle is not part of the superficial anterior compartment of the forearm?

A. FDS
B. FCR
C. Palmaris longus
D. Flexor pollicis longus (FPL) (Correct Answer)

Explanation: **Flexor pollicis longus (FPL)** - The **FPL** is located in the **deep anterior compartment** of the forearm, differentiating it from the superficial muscles [1]. - Its primary function is **flexion of the thumb's interphalangeal joint**, requiring a deeper anatomical position for mechanical advantage [1]. *FDS* - The **Flexor digitorum superficialis (FDS)** is a key muscle of the superficial anterior compartment, visible just beneath the skin and fascia. - It is responsible for **flexing the middle phalanges** of the medial four digits. *FCR* - The **Flexor carpi radialis (FCR)** is situated in the superficial anterior compartment, running obliquely across the forearm. - It functions in **flexion and abduction of the wrist**. *Palmaris longus* - The **Palmaris longus** is a superficial anterior compartment muscle, though it is absent in a significant portion of the population. - When present, its main action is **flexion of the wrist** and tightening of the palmar aponeurosis.

Question 769: Which of the following structures is not found in the midpalmar space?

A. 2nd lumbrical
B. 1st lumbrical (Correct Answer)
C. FDP of 4th finger
D. FDP of 3rd finger

Explanation: ***1st lumbrical*** - The **1st lumbrical** is typically found within the **thenar space** or the **central compartment of the palm**, not the midpalmar space [1]. - Its position is associated with the **index finger's flexor tendons**, which do not traverse the midpalmar space. *2nd lumbrical* - The **2nd lumbrical** is located in the **midpalmar space**, situated on the radial side of the **flexor digitorum profundus (FDP) tendon** to the third digit [1]. - It arises from the radial side of the **FDP tendon** of the **middle finger** [1]. *FDP of 3rd finger* - The **flexor digitorum profundus (FDP) tendon** to the **third finger** (middle finger) passes through the **midpalmar space** [1]. - These tendons, along with their associated lumbricals, are key components of the **midpalmar space**. *FDP of 4th finger* - The **flexor digitorum profundus (FDP) tendon** to the **fourth finger** (ring finger) also travels through the **midpalmar space** [1]. - The midpalmar space contains the **FDP tendons** for the middle, ring, and little fingers, as well as their corresponding lumbricals (2nd, 3rd, and 4th).

Question 770: Axillary nerve is accompanied by which artery ?

A. Posterior circumflex humeral artery (Correct Answer)
B. Axillary artery
C. Subscapular artery
D. Anterior circumflex humeral artery

Explanation: ***Posterior circumflex humeral artery*** - The **axillary nerve** and the **posterior circumflex humeral artery** both pass through the **quadrangular space** in the axilla. - This anatomical relationship makes them vulnerable to injury together, particularly in cases of **shoulder dislocation** or **fractures of the surgical neck of the humerus**. *Axillary artery* - The **axillary artery** is the main arterial trunk of the axilla, but the axillary nerve is not typically described as directly accompanying the main trunk. - While branches of the axillary artery do supply the region where the axillary nerve travels, the specific artery that accompanies the nerve is a direct branch. *Subscapular artery* - The **subscapular artery** is the largest branch of the axillary artery and gives rise to the circumflex scapular and thoracodorsal arteries. - It does not directly accompany the axillary nerve through the quadrangular space; instead, it mostly supplies muscles like the **subscapularis** and **latissimus dorsi**. *Anterior circumflex humeral artery* - The **anterior circumflex humeral artery** also branches from the axillary artery and wraps around the surgical neck of the humerus. - However, it typically runs anteriorly and does not accompany the axillary nerve as it emerges from the quadrangular space posteriorly.

Practice by Chapter

Pectoral Region and Axilla

Practice Questions

Arm and Cubital Fossa

Practice Questions

Forearm and Hand

Practice Questions

Joints of Upper Limb

Practice Questions

Nerves of Upper Limb

Practice Questions

Arterial Supply and Venous Drainage

Practice Questions

Lymphatic Drainage

Practice Questions

Muscles and Their Actions

Practice Questions

Applied Anatomy and Clinical Correlations

Practice Questions

Surface Anatomy and Landmarks

Practice Questions

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free

Upper Limb — MCQs

Upper Limb — MCQs

On this page

Practice by Chapter

Want unlimited practice?