Upper Limb — MCQs

Upper Limb Indian Medical PG Practice Questions and MCQs

Question 321: The superficial branch of the ulnar nerve supplies which of the following muscles?

A. Palmaris brevis (Correct Answer)
B. Opponens pollicis
C. Adductor pollicis
D. Abductor digiti minimi

Explanation: ### Explanation The **ulnar nerve** (C8, T1), often called the "musician’s nerve," enters the hand superficial to the flexor retinaculum via **Guyon’s canal**. At the level of the pisiform bone, it divides into two terminal branches: superficial and deep [1]. **1. Why Palmaris Brevis is Correct:** The **superficial branch** of the ulnar nerve is primarily sensory (supplying the medial 1.5 fingers) but provides motor innervation to exactly one muscle: the **Palmaris brevis** [2]. This small, subcutaneous muscle wrinkles the skin of the hypothenar eminence and improves grip stability [2]. **2. Analysis of Incorrect Options:** * **Opponens pollicis (B):** This is a thenar muscle supplied by the **recurrent branch of the median nerve** [1]. * **Adductor pollicis (C):** Although it is an ulnar-innervated muscle, it is supplied by the **deep branch** of the ulnar nerve. It is a classic "trap" in exams because it is located deep in the palm. * **Abductor digiti minimi (D):** This is a hypothenar muscle. All hypothenar muscles (except Palmaris brevis) are supplied by the **deep branch** of the ulnar nerve [2]. **3. High-Yield Clinical Pearls for NEET-PG:** * **Deep Branch Rule:** The deep branch of the ulnar nerve supplies all intrinsic muscles of the hand **EXCEPT** the three thenar muscles and the lateral two lumbricals (supplied by the Median nerve) and the Palmaris brevis (Supericial branch) [2]. * **Froment’s Sign:** Tests for ulnar nerve palsy; specifically assesses the **Adductor pollicis**. If weak, the patient compensates by flexing the thumb IP joint (using the median-innervated Flexor Pollicis Longus). * **Guyon’s Canal Syndrome:** Compression here can lead to sensory loss in the medial 1.5 fingers and motor weakness of ulnar-innervated intrinsic muscles.

Question 322: Which branch of the subclavian artery contributes to the scapular anastomosis?

A. Vertebral artery
B. Internal thoracic artery
C. Thyrocervical trunk (Correct Answer)
D. Dorsal scapular artery

Explanation: The **scapular anastomosis** is a vital collateral circulation network that allows blood to reach the upper limb if the subclavian or axillary artery is obstructed. It primarily involves three main arterial contributions: 1. **Suprascapular Artery:** Arises from the **Thyrocervical trunk** (a branch of the 1st part of the subclavian artery). 2. **Deep branch of the Transverse Cervical Artery (Dorsal Scapular Artery):** Also typically arises from the **Thyrocervical trunk** (though it can arise directly from the 2nd/3rd part of the subclavian). 3. **Circumflex Scapular Artery:** A branch of the subscapular artery (from the 3rd part of the axillary artery). **Why Option C is correct:** The **Thyrocervical trunk** is the primary source of two out of the three main vessels involved in the anastomosis (Suprascapular and Transverse Cervical arteries). Therefore, it is the most significant parent branch from the subclavian artery contributing to this network. **Why other options are incorrect:** * **A. Vertebral artery:** Supplies the brain and spinal cord; it does not contribute to the scapular region. * **B. Internal thoracic artery:** Supplies the anterior chest wall and mammary glands. * **D. Dorsal scapular artery:** While this artery *is* part of the anastomosis, it is a **branch** of the Transverse Cervical artery (which comes from the Thyrocervical trunk) or a direct branch of the subclavian. In MCQ hierarchy, the "parent" trunk (Thyrocervical) is the preferred answer when identifying the major contributing branch. **NEET-PG High-Yield Pearls:** * **Clinical Significance:** This anastomosis allows blood to bypass a ligation or blockage of the axillary artery occurring between the 1st and 3rd parts. * **Direction of flow:** In cases of proximal occlusion, blood flows in a **retrograde** manner through the circumflex scapular artery to reach the distal axillary artery. * **Mnemonics:** Remember **"S-S-D"** for the Scapular anastomosis: **S**uprascapular, **S**ubscapular (Circumflex branch), and **D**orsal Scapular.

Question 323: Which of the following nerves does not have contributions from roots C5, C6, and C7?

A. Lateral pectoral nerve
B. Musculocutaneous nerve
C. Lateral root of the median nerve
D. Ulnar nerve (Correct Answer)

Explanation: The Brachial Plexus is a high-yield topic for NEET-PG. To answer this question, one must understand the formation of the **Lateral Cord** and the **Medial Cord**. ### **Explanation of the Correct Answer** **D. Ulnar Nerve:** The ulnar nerve is the main branch of the **Medial Cord**. Its primary root values are **C8 and T1**. While it often receives a "communicating branch" from the lateral root of the median nerve (carrying C7 fibers) in about 50% of individuals, its classic anatomical description excludes C5 and C6. Therefore, it does not share the C5-C6-C7 distribution characteristic of the lateral cord branches. ### **Analysis of Incorrect Options** The Lateral Cord is formed by the union of the anterior divisions of the upper (C5, C6) and middle (C7) trunks. Consequently, all its branches typically carry **C5, C6, and C7** fibers: * **A. Lateral Pectoral Nerve:** A direct branch of the lateral cord (C5, C6, C7). It supplies the pectoralis major [1]. * **B. Musculocutaneous Nerve:** The terminal branch of the lateral cord (C5, C6, C7). It supplies the coracobrachialis, biceps brachii, and brachialis. * **C. Lateral Root of the Median Nerve:** One of the two heads forming the median nerve; it arises from the lateral cord and carries fibers from C5, C6, and C7. ### **High-Yield Clinical Pearls for NEET-PG** * **Mnemonic for Lateral Cord Branches:** "Lucy Loves Me" (Lateral pectoral, Lateral root of median nerve, Musculocutaneous). All are **C5-C7**. * **The "M" Shape:** The brachial plexus forms an 'M' over the axillary artery, consisting of the Musculocutaneous nerve, Median nerve, and Ulnar nerve. * **Ulnar Nerve Paradox:** Despite being C8-T1, the ulnar nerve is often described as having C7 fibers for the flexor carpi ulnaris; however, it never contains C5 or C6.

Question 324: Damage to the axillary nerve is most commonly caused by fractures of which part of the humerus?

A. Shaft of the humerus
B. Surgical neck of the humerus (Correct Answer)
C. Medial epicondyle
D. Lateral epicondyle

Explanation: **Explanation:** The **axillary nerve (C5-C6)**, a branch of the posterior cord of the brachial plexus, travels through the quadrangular space and winds around the **surgical neck of the humerus** alongside the posterior circumflex humeral artery. Because of this intimate anatomical relationship, fractures at the surgical neck or anterior dislocations of the shoulder joint frequently result in axillary nerve injury. This leads to paralysis of the deltoid and teres minor muscles, resulting in loss of shoulder abduction (beyond 15 degrees) and sensory loss over the "regimental badge area." **Analysis of Incorrect Options:** * **Shaft of the humerus:** This is the classic site for injury to the **radial nerve**, which travels in the spiral (radial) groove. Damage here leads to "wrist drop." * **Medial epicondyle:** Fractures or compression at this site involve the **ulnar nerve** as it passes posteriorly in the ulnar groove. Damage results in "claw hand" and sensory loss in the medial 1.5 fingers. * **Lateral epicondyle:** While less commonly associated with a specific major nerve trunk injury compared to the others, it serves as the origin for the common extensor tendon. Nerve injuries in the supracondylar region typically involve the median or radial nerves. **High-Yield Clinical Pearls for NEET-PG:** * **Nerve-Bone Relationships:** Remember the "ARM" mnemonic for humerus fractures (Proximal to Distal): **A**xillary (Surgical Neck), **R**adial (Spiral Groove/Shaft), **M**edian/Ulnar (Supracondylar/Medial Epicondyle). * **Clinical Sign:** Axillary nerve damage is characterized by the loss of the rounded contour of the shoulder due to deltoid atrophy. * **Quadrangular Space Boundaries:** Superior (Teres minor), Inferior (Teres major), Medial (Long head of triceps), Lateral (Surgical neck of humerus).

Question 325: Which of the following two muscles are crossed by the Extensor Carpi Radialis Longus?

A. Abductor Pollicis Longus and Extensor Pollicis Brevis (Correct Answer)
B. Extensor Digitorum and Extensor Indicis
C. Abductor Pollicis Longus and Extensor Indicis
D. Brachioradialis and Extensor Digiti Minimi

Explanation: **Explanation:** The correct answer is **Option A: Abductor Pollicis Longus (APL) and Extensor Pollicis Brevis (EPB).** This question tests your knowledge of the **"Outcropping Muscles"** of the forearm and the anatomical arrangement of the extensor compartments. The Extensor Carpi Radialis Longus (ECRL) and Extensor Carpi Radialis Brevis (ECRB) originate from the lateral supracondylar ridge and epicondyle, respectively. As they descend toward the wrist to enter the second extensor compartment, they are superficially crossed by the tendons of the **APL and EPB** [1]. These two muscles "outcrop" from the deep plane of the posterior forearm to reach the thumb, passing obliquely over the radial extensors. **Analysis of Incorrect Options:** * **Option B & C:** The Extensor Indicis and Extensor Digitorum lie medial to or in a deeper plane relative to the path of the ECRL at the distal forearm; they do not cross over it [1]. * **Option D:** The Brachioradialis lies lateral to the ECRL, and the Extensor Digiti Minimi is located in the fifth compartment, far medial to the radial extensors [1]. **High-Yield NEET-PG Pearls:** 1. **De Quervain’s Tenosynovitis:** This clinical condition involves inflammation of the synovial sheaths of the APL and EPB (the first extensor compartment) [1]. 2. **Intersection Syndrome:** Pain and swelling at the site where the APL and EPB cross over the ECRL/ECRB (approximately 4cm proximal to the tubercle of Lister). 3. **Anatomical Snuffbox:** The APL and EPB form the lateral (anterior) boundary, while the Extensor Pollicis Longus (EPL) forms the medial (posterior) boundary [1]. The ECRL and ECRB tendons form the floor of the snuffbox.

Question 326: Which nerve supplies the adductor pollicis muscle?

A. Median nerve
B. Radial nerve
C. Superficial branch of the ulnar nerve
D. Deep branch of the ulnar nerve (Correct Answer)

Explanation: The **adductor pollicis** is a unique muscle of the hand. While it acts on the thumb, it is not a thenar muscle; it belongs to the **adductor-interosseous compartment**. **1. Why the Correct Answer is Right:** The **deep branch of the ulnar nerve (C8, T1)** is the primary motor nerve of the hand. After passing through Guyon’s canal, it pierces the hypothenar muscles and travels across the palm along the deep palmar arch. It supplies all the interossei, the medial two lumbricals, the hypothenar muscles, and terminates by supplying the **adductor pollicis** [1]. This is a classic "high-yield" exception because most thumb muscles are supplied by the median nerve. **2. Why Other Options are Incorrect:** * **Median Nerve:** Supplies the "LOAF" muscles (Lateral two lumbricals, Opponens pollicis, Abductor pollicis brevis, and Flexor pollicis brevis) [1]. It does *not* supply the adductor pollicis. * **Radial Nerve:** Primarily supplies the extensor compartment of the forearm and provides sensory innervation to the dorsum of the hand [2]. It does not supply any intrinsic muscles of the hand. * **Superficial branch of the ulnar nerve:** This branch is primarily sensory (to the medial 1.5 fingers) and motor only to the **palmaris brevis** [1]. **3. Clinical Pearls for NEET-PG:** * **Froment’s Sign:** When the ulnar nerve is paralyzed, the patient cannot adduct the thumb to hold a piece of paper. Instead, they flex the thumb at the IP joint (using the Flexor Pollicis Longus, supplied by the Median nerve) to compensate. This is a positive Froment’s sign. * **Mnemonic:** The Ulnar nerve is the **"Musician’s Nerve"** because it controls fine movements of the intrinsic hand muscles. * **Rule of Thumb:** All intrinsic muscles of the hand are supplied by the deep branch of the ulnar nerve EXCEPT the thenar muscles and lateral two lumbricals (Median nerve).

Question 327: Ulnar paradox is seen in which of the following conditions?

A. High ulnar nerve palsy (Correct Answer)
B. Low ulnar nerve palsy
C. Combined median and ulnar nerve palsy
D. Guyon's canal entrapment of ulnar nerve

Explanation: The **Ulnar Paradox** refers to the clinical observation that a higher (more proximal) lesion of the ulnar nerve results in a **less severe** physical deformity (claw hand) than a lower (more distal) lesion. **1. Why High Ulnar Nerve Palsy is Correct:** In a **High Lesion** (at or above the elbow), the nerve supply to the **Flexor Digitorum Profundus (FDP)** of the ring and little fingers is lost. Since the FDP is responsible for flexing the Distal Interphalangeal (DIP) joints, its paralysis means the fingers remain relatively straight. This makes the "clawing" appearance less prominent, despite the injury being more proximal. **2. Why the Incorrect Options are Wrong:** * **Low Ulnar Nerve Palsy:** In a low lesion (at the wrist), the FDP remains intact while the lumbricals are paralyzed. The intact FDP continues to flex the DIP joints forcefully, while the unopposed extensors hyperextend the MCP joints. This results in a **more pronounced** and "ugly" claw hand. * **Combined Median and Ulnar Nerve Palsy:** This results in a "Total Claw Hand" involving all four fingers, but it does not define the specific "paradox" related to the level of ulnar nerve injury. * **Guyon’s Canal Entrapment:** This is a type of low ulnar nerve palsy. It would result in severe clawing, not the paradoxical reduction of deformity seen in high lesions. **Clinical Pearls for NEET-PG:** * **The Rule:** "The closer the lesion is to the paw, the worse the claw." * **Ulnar Claw Hand:** Characterized by hyperextension at MCP joints and flexion at IP joints (4th and 5th digits). * **Froment’s Sign:** Tests for adductor pollicis paralysis (ulnar nerve); the patient compensates by flexing the thumb IP joint using the Flexor Pollicis Longus (median nerve).

Question 328: Which of the following parts of the brachial plexus is involved in Klumpke's paralysis?

A. Upper trunk
B. Middle trunk
C. Lower trunk (Correct Answer)
D. None of the above

Explanation: ### Explanation **Correct Option: C (Lower trunk)** **Medical Concept:** Klumpke’s paralysis is a lower brachial plexus injury resulting from excessive abduction of the arm (e.g., a person falling from a height and clutching a tree branch, or during a difficult birth/breech delivery). This mechanism causes traction or avulsion of the **C8 and T1 nerve roots**, which together form the **Lower Trunk** of the brachial plexus. The T1 fibers specifically supply the intrinsic muscles of the hand. Damage leads to paralysis of the lumbricals, interossei, and thenar/hypothenar muscles. This results in the characteristic clinical sign: **"Total Claw Hand"** (hyperextension at the MCP joints and flexion at the IP joints). **Analysis of Incorrect Options:** * **A. Upper Trunk:** Injury to the upper trunk (C5-C6) results in **Erb’s Paralysis**. This typically presents with the "Waitman’s Tip" or "Policeman’s Tip" deformity (arm adducted, medially rotated, and forearm extended/pronated). * **B. Middle Trunk:** Isolated middle trunk (C7) injuries are rare. Damage here would primarily affect the radial nerve distribution, leading to weakness in elbow, wrist, and finger extension. **High-Yield Clinical Pearls for NEET-PG:** * **Site of Injury:** Lower Trunk (C8, T1). * **Deformity:** Total Claw Hand (due to loss of lumbricals). * **Sensory Loss:** Along the ulnar border of the forearm and hand. * **Horner’s Syndrome:** Often associated with Klumpke’s paralysis because the T1 sympathetic fibers (preganglionic) may be damaged, leading to miosis, ptosis, and anhidrosis. * **Contrast:** Erb's = "Up" (Upper trunk/C5-C6); Klumpke's = "Down" (Lower trunk/C8-T1).

Question 329: Which of the following muscles is NOT attached to the coracoid process of the scapula?

A. Coracobrachialis
B. Short head of biceps
C. Pectoralis minor
D. Long head of triceps (Correct Answer)

Explanation: The **coracoid process** of the scapula is a crucial bony landmark in the upper limb, serving as an attachment point for three muscles and several ligaments. ### **Why Option D is Correct** The **Long head of triceps** does not attach to the coracoid process. Instead, it originates from the **infraglenoid tubercle** of the scapula. It is the only head of the triceps that crosses the shoulder joint, acting as an adductor and extensor of the arm. ### **Why Other Options are Incorrect** The coracoid process serves as the origin for two muscles and the insertion for one: * **Coracobrachialis (Option A):** Originates from the tip of the coracoid process (along with the short head of biceps). * **Short head of biceps (Option B):** Originates from the tip of the coracoid process. * **Pectoralis minor (Option C):** Inserts into the medial border and upper surface of the coracoid process. ### **High-Yield NEET-PG Pearls** * **The "Triple Attachment":** Remember the mnemonic **"B-C-P"** for muscles on the coracoid (Biceps short head, Coracobrachialis, Pectoralis minor). * **Ligamentous Attachments:** The coracoid process also provides attachment to the **Coracoacromial**, **Coracohumeral**, and **Coracoclavicular** (Conoid and Trapezoid) ligaments. * **Surgical Landmark:** The coracoid process is often called the "Surgeon's Lighthouse" because it serves as a guide to avoid neurovascular structures (like the brachial plexus) during shoulder surgery. * **Ossification:** It is a classic example of an **atavistic epiphysis** (a bone that was once independent in lower animals but is now fused to another bone in humans).

Question 330: Which of the following is not a component of the carpal tunnel?

A. Ulnar nerve (Correct Answer)
B. Median nerve
C. Flexor digitorum superficialis
D. Flexor digitorum profundus

Explanation: The **carpal tunnel** is a fibro-osseous gateway located at the wrist, formed by the carpal bones (arch) and the **flexor retinaculum** (roof). Understanding its contents is high-yield for NEET-PG. [1] ### Why the Ulnar Nerve is the Correct Answer The **ulnar nerve** (and the ulnar artery) does **not** pass through the carpal tunnel. Instead, it travels superficial to the flexor retinaculum through a separate anatomical space known as **Guyon’s canal** (ulnar canal). [1] Therefore, it is not affected by carpal tunnel syndrome. ### Analysis of Other Options (Contents of the Tunnel) The carpal tunnel contains exactly **10 structures**: * **Median Nerve (Option B):** The most superficial and clinically significant structure in the tunnel. [1] Compression of this nerve leads to Carpal Tunnel Syndrome (CTS). * **Flexor Digitorum Superficialis (Option C):** Four tendons of the FDS pass through the tunnel, arranged in two layers (middle and ring finger tendons are superficial to index and little finger tendons). * **Flexor Digitorum Profundus (Option D):** Four tendons of the FDP pass through the tunnel deep to the FDS. [2] * **Flexor Pollicis Longus:** One single tendon (the 10th structure) passes through its own synovial sheath on the radial side. [2] ### High-Yield Clinical Pearls for NEET-PG * **Guyon’s Canal:** Formed by the pisiform and the hook of the hamate. Compression here affects the ulnar nerve (Claw hand). * **Flexor Carpi Radialis (FCR):** Often a "trap" option; it travels in its own separate compartment within the lateral attachment of the flexor retinaculum and is technically **not** inside the carpal tunnel. [3] * **CTS Symptoms:** Characterized by paresthesia in the lateral 3.5 digits and wasting of the **Thenar muscles** (LOAF muscles), but the **palmar cutaneous branch** of the median nerve is spared as it passes superficial to the retinaculum. [1], [2]

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?