Upper Limb Practice Questions

Q: Which muscles are supplied by the ulnar nerve?

All of the options. ***All of the options*** - The **ulnar nerve** supplies the **intrinsic muscles of the hand**, excluding the three thenar muscles (Abductor pollicis brevis, Flexor pollicis brevis-superficial head, Opponens pollicis) and the lateral two lumbricals (1st and 2nd). - The complete list of intrinsic hand muscles supplied by the ulnar nerve includes all interossei (dorsal and palmar), the hypothenar muscles (Abductor digiti minimi, Flexor digiti minimi brevis, Opponens digiti minimi), the third and fourth lumbricals, the palmaris brevis, the adductor pollicis, and the deep head of the flexor pollicis brevis [1]. *Dorsal interossei* - There are four **dorsal interossei** muscles, responsible for **ABduction** (DAB) of the fingers. - All four dorsal interossei are solely supplied by the **deep branch of the ulnar nerve**. *4th lumbrical* - The **lumbricals** are small muscles that flex the MCP joints and extend the IP joints [1]. - The **medial two lumbricals** (3rd and 4th) are supplied by the **deep branch of the ulnar nerve**, while the lateral two are supplied by the median nerve. *Abductor digiti minimi* - This is one of the three **hypothenar muscles** (muscles of the little finger eminence). - Like the other hypothenar muscles, it is exclusively supplied by the **deep branch of the ulnar nerve** [1].

Q: During hyperextension, the long head of triceps gets detached from which site?

Infraglenoid tubercle. ***Infraglenoid tubercle*** - The **long head of the triceps brachii** muscle originates from the **infraglenoid tubercle** of the scapula. - Violent or sudden hyperextension of the shoulder places maximum tensile stress on this specific origin site, predisposing it to avulsion or detachment. *Supraglenoid tubercle* - This tubercle is the origin point for the **long head of the biceps brachii** muscle, which is not the muscle relevant to this injury scenario. - Injuries involving the supraglenoid tubercle are classically associated with **SLAP lesions** and glenohumeral instability. *Shaft of humerus* - The **medial and lateral heads** of the triceps originate along the posterior surface of the shaft of the humerus. - These muscular origins are less prone to acute avulsion during hyperextension compared to the tendinous long head origin on the scapula. *Olecranon process* - The olecranon process of the ulna is the **insertion** point for all three heads of the triceps, not the origin. - Detachment at this site typically occurs due to direct impact or strong eccentric contraction during forced elbow flexion, often resulting in an **olecranon fracture**.

Q: What is incorrect about the test being performed?

Due to action of flexor pollicis brevis. ***Due to action of flexor pollicis brevis (INCORRECT STATEMENT)*** - This is the **incorrect statement** about Froment's sign. - The compensatory thumb flexion is due to **flexor pollicis longus** (innervated by the anterior interosseous nerve, a branch of the median nerve), NOT flexor pollicis brevis. - Flexor pollicis brevis is innervated primarily by the recurrent branch of the median nerve and does not flex the interphalangeal joint. *Froment sign (Correct)* - The image depicts the characteristic **Froment's sign**, used to assess **ulnar nerve palsy**. - This is a correct description of the test being performed. - The sign demonstrates weakness of the **adductor pollicis** muscle. *Flexion of interphalangeal joint of thumb (Correct)* - The image shows **flexion at the interphalangeal joint of the thumb**. - This is a correct observation of the compensatory mechanism. - This flexion occurs to maintain grip strength when adductor pollicis is weak. *Due to paralysis of adductor pollicis (Correct)* - This correctly identifies the underlying pathology. - The **adductor pollicis muscle** (innervated by the **ulnar nerve**) is paralyzed or weak. - This muscle is primarily responsible for **thumb adduction**, and its weakness leads to the compensatory mechanism seen in Froment's sign.

Q: Identify the structure marked as X in the specimen of left cubital fossa

Brachial artery. ***Brachial artery*** - The structure marked X is a prominent, thick-walled vessel consistent with the **brachial artery**, which passes through the cubital fossa. - The brachial artery is typically found medial to the **biceps brachii tendon** and lateral to the **median nerve** in the cubital fossa. *Biceps brachii* - The **biceps brachii** is a muscle, and while its tendon passes through the cubital fossa, the structure marked X is clearly a vessel, not a muscle or tendon. - The biceps brachii muscle is usually much larger and fleshy, not a defined linear structure like X. *Radial recurrent artery* - The **radial recurrent artery** is a smaller branch arising from the radial artery, which subsequently branches off the brachial artery. - It is significantly smaller and less prominent than the structure marked X, which appears to be a main vessel. *Posterior interosseous nerve* - The **posterior interosseous nerve** is a branch of the radial nerve and is primarily a nerve structure, which appears white/yellowish and thinner than the structure marked X, which is a blood vessel. - It typically winds around the neck of the radius and passes into the posterior compartment of the forearm, not usually as prominently displayed within the cubital fossa in this manner.

Q: Identify the function of the muscles marked in red:

Flexion at MCP joint. ***Flexion at MCP joint*** - The muscles shown in red are the **lumbricals**, which primarily function to **flex the metacarpophalangeal (MCP) joints** and **extend the interphalangeal (IP) joints**. - This is their most fundamental action when identifying lumbrical function, as they originate from **flexor digitorum profundus tendons** and insert into the **extensor expansion**, providing precise **MCP joint flexion**. - This unique action creates the **"lumbrical grip"** essential for precision handling. *Flexion at IP joint* - Lumbricals actually **extend the interphalangeal (IP) joints**, not flex them, making this option anatomically incorrect. - **Flexion at IP joints** is performed by the **flexor digitorum superficialis** (PIP joints) and **flexor digitorum profundus** (DIP joints). - The lumbrical insertion into the **extensor hood** produces IP extension, the opposite of this option. *Extension at MCP joint* - **Extension at the MCP joints** is primarily performed by the **extensor digitorum** and other **extrinsic extensor muscles**. - Lumbricals produce the opposite action, **flexing the MCP joints** rather than extending them. *Abduction at MCP joint* - **Abduction at the MCP joints** is primarily performed by the **dorsal interossei muscles** using the **DAB** (Dorsal ABduct) mnemonic. - Lumbricals do not contribute to **finger abduction** but rather focus on **MCP flexion, IP extension**, and **fine motor control**.

Q: Name the muscle marked as colour blue in the extensor compartment of forearm. (Recent NEET Pattern 2019)

Brachioradialis. ***Brachioradialis*** - The **brachioradialis** muscle is a prominent superficial muscle in the lateral compartment of the forearm, shown in **blue** in the diagram, originating from the **lateral supracondylar ridge of the humerus** and inserting into the **radial styloid process**. - It primarily functions to **flex the elbow** and helps to bring the forearm into a midprone position. *Extensor carpi radialis* - The extensor carpi radialis muscles (longus and brevis) are located deep to the brachioradialis and extend the wrist, often distinguishable by their more distal insertion on the **metacarpals**. - They are typically not the most superficial and most lateral muscle spanning the entire forearm length as depicted in blue. *Extensor digitorum* - The **extensor digitorum** is located more medially than the brachioradialis and its tendons diverge to attach to the four medial fingers, a configuration not shown by the blue muscle. - This muscle is responsible for **extending the medial four digits**. *Extensor carpi ulnaris* - The **extensor carpi ulnaris** is situated on the **ulnar side** of the forearm, furthest from the blue-highlighted muscle, and its primary action is **wrist extension and ulnar deviation**. - It would be found along the posterior medial aspect of the forearm, not in the relatively lateral position shown in blue.

Q: Which nerve gives sensory supply to the region marked with an arrow?

Radial nerve. ***Radial nerve*** - The image shows the **dorsal (back) aspect of the hand**, specifically the region over the **anatomical snuffbox** or the dorsal part of the thumb and first web space. - The **superficial branch of the radial nerve** provides sensory innervation to this area, including the dorsal aspect of the thumb, index, and half of the middle finger, extending to the dorsal hand. *Median nerve* - The **median nerve** primarily provides sensory innervation to the **palmar aspect** of the lateral three and a half digits (thumb, index, middle, and radial half of the ring finger) and the corresponding palm. - It does not innervate the dorsal hand in the region indicated. *Ulnar nerve* - The **ulnar nerve** innervates the **medial 1.5 digits** (pinky and ulnar half of the ring finger) on both the palmar and dorsal aspects of the hand, as well as the ulnar part of the palm and dorsum of the hand. - The highlighted region is on the radial side of the hand, not the ulnar side. *Posterior interosseous nerve* - The **posterior interosseous nerve** is a **motor nerve** that innervates the muscles in the posterior compartment of the forearm. - It does **not provide sensory innervation** to any part of the hand.

Q: The image shows flexion at PIP and extension at DIP, which is suggestive of presence of:

Boutonniere deformity. ***Boutonniere deformity*** - This deformity is characterized by **flexion of the proximal interphalangeal (PIP) joint** and **hyperextension of the distal interphalangeal (DIP) joint** - Results from disruption of the **central slip of the extensor tendon** at the PIP joint - Commonly seen in **rheumatoid arthritis**, trauma, or inflammatory conditions - The lateral bands slip volarly, causing the characteristic deformity pattern *Swan neck deformity* - Shows the **opposite pattern**: hyperextension at PIP joint and flexion at DIP joint - Not consistent with the described clinical findings of PIP flexion and DIP extension - Also commonly associated with rheumatoid arthritis but has different mechanism *Mallet finger* - Characterized by **isolated DIP joint flexion** with inability to actively extend - Results from disruption of the extensor tendon at its insertion on the distal phalanx - Does not involve PIP joint abnormality as described in the image *Trigger finger* - Presents with **catching or locking during finger flexion/extension** - Involves flexor tendon entrapment, not a fixed deformity pattern - Does not produce the specific PIP flexion with DIP extension pattern shown

Q: The inability to flex the index finger is a sign of

Median nerve injury. ***Median nerve injury*** - The **median nerve** innervates the **flexor digitorum superficialis** and the **flexor digitorum profundus** (radial half), which are responsible for flexing the index and middle fingers. [1] - Damage to this nerve at a high level (e.g., above the elbow) would impact these muscles, leading to an **inability to flex the index finger**. [1] *Radial nerve injury* - The **radial nerve** primarily innervates the **extensor muscles** of the arm and forearm. - Injury to this nerve would result in difficulty extending the wrist and fingers (e.g., **wrist drop**), not flexing them. *Ulnar nerve injury* - The **ulnar nerve** innervates the **flexor carpi ulnaris** and the **ulnar half of the flexor digitorum profundus** (ring and pinky finger). [1] - Damage would primarily affect the flexion of the ring and little fingers, as well as intrinsic hand muscles, leading to a **claw hand deformity**. *Dupuytren's contracture* - This condition involves **fibrosis and thickening of the palmar fascia**, causing the fingers (most commonly the ring and little fingers) to permanently flex towards the palm. - It is a **fibroproliferative disorder** of the hand, not a nerve injury, and typically affects flexibility in multiple fingers in a characteristic pattern, rather than a specific inability to flex one finger due to paralysis.

Question 1

Which muscles are supplied by the ulnar nerve?

Accepted Answer

All of the options

Answer

Dorsal interossei

Answer

4th lumbrical

Answer

Abductor digiti minimi

Question 2

During hyperextension, the long head of triceps gets detached from which site?

Accepted Answer

Infraglenoid tubercle

Answer

Supraglenoid tubercle

Answer

Shaft of humerus

Answer

Olecranon process

Question 3

What is incorrect about the test being performed?

Accepted Answer

Due to action of flexor pollicis brevis

Answer

Froment sign

Answer

Flexion of interphalangeal joint of thumb

Answer

Due to paralysis of adductor pollicis

Question 4

Identify the structure marked as X in the specimen of left cubital fossa

Accepted Answer

Brachial artery

Answer

Biceps brachii

Answer

Radial recurrent artery

Answer

Posterior interosseous nerve

Question 5

All are true about the triangle marked green except:

Accepted Answer

Medial border is formed by tendon of abductor pollicis longus and extensor pollicis brevis

Answer

Localised pain in this area after fall on outstretched hand indicates fracture of scaphoid

Answer

Cephalic vein in this area is used to make Ciminobrescia fistula in hemodialysis

Answer

Superficial branch of radial nerve runs to provide innervation to 3.5 digits

Question 6

Identify the function of the muscles marked in red:

Accepted Answer

Flexion at MCP joint

Answer

Flexion at IP joint

Answer

Extension at MCP joint

Answer

Abduction at MCP joint

Question 7

Name the muscle marked as colour blue in the extensor compartment of forearm. (Recent NEET Pattern 2019)

Accepted Answer

Brachioradialis

Answer

Extensor carpi radialis

Answer

Extensor digitorum

Answer

Extensor carpi ulnaris

Question 8

Which nerve gives sensory supply to the region marked with an arrow?

Accepted Answer

Radial nerve

Answer

Median nerve

Answer

Ulnar nerve

Answer

Posterior interosseous nerve

Question 9

The image shows flexion at PIP and extension at DIP, which is suggestive of presence of:

Accepted Answer

Boutonniere deformity

Answer

Swan neck deformity

Answer

Mallet finger

Answer

Trigger finger

Question 10

The inability to flex the index finger is a sign of

Accepted Answer

Median nerve injury

Answer

Radial nerve injury

Answer

Ulnar nerve injury

Answer

Dupuytren's contracture

Upper Limb — MCQs

Upper Limb — MCQs

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