Upper Limb Practice Questions

Q: Inability to pronate forearm is due to injury to which nerve ?

Median. Median nerve - The median nerve innervates the pronator teres and pronator quadratus muscles, which are the primary muscles responsible for forearm pronation. - Damage to the median nerve would therefore lead to an inability or significant difficulty in performing this action. Ulnar - The ulnar nerve primarily controls most intrinsic muscles of the hand and some forearm flexors, but it does not play a direct role in forearm pronation. - Injury to the ulnar nerve would typically manifest as weakness in finger adduction/abduction and wrist flexion, not pronation issues. Radial - The radial nerve innervates the supinator muscle and the extensors of the forearm and hand, facilitating forearm supination and wrist/finger extension. - Damage to the radial nerve would impair supination and extension, not pronation. Musculocutaneous - The musculocutaneous nerve innervates the biceps brachii, brachialis, and coracobrachialis muscles, which are primarily involved in flexion of the elbow and supination of the forearm (biceps). - Injury to this nerve would compromise flexion and supination, but not pronation directly.

Q: Index finger infection spreads to?

Mid palmar space. ***Mid palmar space*** - Infections of the **index, middle, and ring fingers** predominantly spread to the **midpalmar space** due to the anatomical connections of their **flexor tendon sheaths**. - The flexor sheath of these fingers usually terminates just distal to the **carpal tunnel**, making the midpalmar space the most common site for proximal spread of infection. *Thenar space* - Infections of the **thumb** typically spread to the **thenar space** because its flexor tendon sheath extends directly into this space. - The thenar space is located between the **adductor pollicis muscle** and the **flexor tendons** of the other fingers. *Hypothenar space* - The **hypothenar space** is located on the ulnar side of the hand, overlying the hypothenar muscles. - While it is an anatomically defined space, it is not the primary site for spread of **index finger infections**, which follow the midpalmar route. *Flexion space* - "Flexion space" is not a recognized anatomical term for a fascial space in the hand where infections commonly spread. - Infections in the hand typically follow the **flexor tendon sheaths** and then extend into specific deep palmar spaces.

Q: Anterior axillary fold is due to which muscle?

Pectoralis major. ***Pectoralis major*** - The **pectoralis major muscle** forms the bulk of the chest and constitutes the anterior wall of the axilla, hence it forms the **anterior axillary fold** [1]. - Its large size and superficial position make it the primary anatomical structure defining this fold [1]. *Pectoralis minor* - The **pectoralis minor** is a smaller muscle located beneath the pectoralis major and does not contribute significantly to the surface anatomy of the axillary fold [2]. - It plays a role in stabilizing the scapula but is not palpable as part of the anterior axillary fold. *Subscapularis* - The **subscapularis muscle** is part of the rotator cuff and is located on the anterior surface of the scapula, deep within the axilla. - It lies too deep to contribute to the visible surface anatomy of the axillary folds. *Teres major* - The **teres major muscle** forms the inferior border of the posterior wall of the axilla, in conjunction with the latissimus dorsi. - It contributes to the **posterior axillary fold**, not the anterior one.

Q: Skin over hypothenar eminence is supplied by?

Ulnar nerve. ***Ulnar nerve*** - The **hypothenar eminence** and the medial side of the palm are innervated by the **ulnar nerve** for sensory input [1]. - The **superficial branch of the ulnar nerve** provides sensory innervation to this region [1]. *Radial nerve* - The **radial nerve** primarily supplies the dorsum of the hand and the lateral aspect of the forearm. - It does not innervate the **hypothenar eminence**. *Median nerve* - The **median nerve** innervates the lateral palm, thumb, index, middle, and radial half of the ring finger [1]. - It does not provide sensation to the **hypothenar eminence**. *Anterior interosseous nerve* - The **anterior interosseous nerve** is a branch of the median nerve and is purely motor. - It supplies deep muscles in the forearm and has **no sensory innervation** to the hand.

Q: Which nerves primarily supply the small muscles of the hand?

Ulnar and Median Nerves. The ulnar nerve innervates most intrinsic hand muscles, including the hypothenar muscles, interossei, and the medial two lumbricals [1]. The median nerve innervates the thenar muscles (excluding adductor pollicis), and the lateral two lumbricals, essential for fine motor skills [1]. While the radial nerve provides sensory innervation to part of the hand, its motor supply to intrinsic hand muscles is minimal [2].

Q: Which structure is described as intracapsular but extrasynovial in the shoulder joint?

Long head of biceps. ***Long head of biceps*** - The tendon of the **long head of the biceps brachii muscle** runs through the **capsule of the shoulder joint** to attach to the supraglenoid tubercle. - While it is located within the joint capsule (intracapsular), it is **surrounded by a synovial sheath** (an invagination of the synovial membrane that separates it from the main joint cavity), classifying it as **extrasynovial**. - This means the tendon passes through the joint but is not directly bathed in the synovial fluid of the main joint space. *Long head of triceps* - The **long head of the triceps brachii** originates from the **infraglenoid tubercle** of the scapula, which is **extra-articular** relative to the shoulder joint. - Therefore, it is neither intracapsular nor extrasynovial within the shoulder joint. *Short head of biceps* - The **short head of the biceps brachii** originates from the **coracoid process** of the scapula. - This origin is located **outside the shoulder joint capsule**, making it a completely extra-articular structure. *Coracobrachialis* - The **coracobrachialis muscle** originates from the **coracoid process** of the scapula. - This origin is also **outside the shoulder joint capsule**, placing it entirely extra-articular.

Q: Boundaries of quadrilateral space include all EXCEPT:

Deltoid. ***Deltoid*** - The **deltoid muscle** overlies the shoulder joint and does not form a boundary for the quadrilateral space. - Its primary actions are **abduction**, flexion, and extension of the arm, but it is not directly involved in defining this specific anatomical passageway. *Teres major* - The **teres major muscle** forms the inferior border of the quadrilateral space. - It separates the quadrilateral space from the lower triangular space. *Long head of triceps* - The **long head of the triceps brachii muscle** forms the medial border of the quadrilateral space. - It also separates the quadrilateral space from the upper triangular space. *Neck of humerus* - The **surgical neck of the humerus** forms the lateral boundary of the quadrilateral space. - The **axillary nerve** and **posterior circumflex humeral artery** pass through this space, wrapping around the surgical neck of the humerus.

Q: Olecranon process of ulna helps in formation of?

Trochlear notch. ***Trochlear notch*** - The olecranon process forms the superior prominence of the ulna and contributes significantly to the posterior boundary of the **trochlear notch**. - This notch articulates with the **trochlea of the humerus** to form part of the elbow joint, allowing for hinge-like movements. *Radial notch* - The **radial notch** is a small, concave articular facet located on the lateral side of the coronoid process of the ulna, and it articulates with the head of the radius. - It is distinct from the olecranon process, which is positioned proximally to it. *Olecranon fossa* - The **olecranon fossa** is a depression on the posterior aspect of the distal humerus, not a part of the ulna itself. - During elbow extension, the olecranon process of the ulna fits into this fossa. *Coronoid fossa* - The **coronoid fossa** is a depression on the anterior aspect of the distal humerus, superior to the trochlea. - It accommodates the **coronoid process of the ulna** during elbow flexion, not the olecranon process.

Q: Which muscle primarily forms the posterior wall of the axilla?

Subscapularis. ***Subscapularis*** - The **subscapularis** muscle forms the **largest and superior part of the posterior wall of the axilla**. - It arises from the subscapular fossa on the anterior surface of the scapula and its broad surface creates the majority of the posterior axillary wall. - It is a key component of the rotator cuff and passes through the axilla to insert on the lesser tubercle of the humerus. *Latissimus dorsi* - The **latissimus dorsi** contributes to the **inferior part of the posterior wall** of the axilla [1]. - Along with teres major, it forms the lower border of the posterior wall, but does not form the primary or largest component [1]. *Teres major* - The **teres major** also forms part of the **inferior portion of the posterior wall**, lying superior to latissimus dorsi. - Together with latissimus dorsi, it contributes to the lower aspect of the posterior wall. *Pectoralis major* - The **pectoralis major** forms the **anterior wall of the axilla**, not the posterior wall [1]. - It is a large, fan-shaped muscle essential for adduction and medial rotation of the humerus [1].

Q: What is the nerve root value of the supinator reflex (brachioradialis reflex)?

C5 C6. ***C5 C6*** - The supinator reflex, also known as the **brachioradialis reflex**, is primarily mediated by the **C5 and C6 nerve roots**. - Tapping the **brachioradialis tendon** elicits a reflexive forearm supination and elbow flexion, confirming the integrity of this root level. *C3 C4* - These nerve roots are primarily involved with the **diaphragm** (via the phrenic nerve) and neck muscles. - They do not contribute significantly to the innervation of the muscles involved in the supinator reflex. *C4 C5* - While C5 is involved, C4 primarily innervates muscles of the **neck and shoulder girdle** such as the **levator scapulae** and **supraspinatus**. - The main contribution to the supinator reflex arc requires the combined input from C5 and C6. *C8 T1* - These nerve roots are primarily responsible for the innervation of the **intrinsic hand muscles** and some forearm flexors. - They are tested by reflexes such as the **triceps reflex (C7)** and finger flexion reflexes, not the supinator reflex.

Question 1

Inability to pronate forearm is due to injury to which nerve ?

Accepted Answer

Median

Answer

Ulnar

Answer

Radial

Answer

Musculocutaneous

Question 2

Index finger infection spreads to?

Accepted Answer

Mid palmar space

Answer

Hypothenar space

Answer

Flexion space

Answer

Thenar space

Question 3

Anterior axillary fold is due to which muscle?

Accepted Answer

Pectoralis major

Answer

Pectoralis minor

Answer

Subscapularis

Answer

Teres major

Question 4

Skin over hypothenar eminence is supplied by?

Accepted Answer

Ulnar nerve

Answer

Radial nerve

Answer

Median nerve

Answer

Anterior interosseous nerve

Question 5

Which nerves primarily supply the small muscles of the hand?

Accepted Answer

Ulnar and Median Nerves

Answer

Radial nerve

Answer

Axillary nerve

Answer

Musculocutaneous nerve

Question 6

Which structure is described as intracapsular but extrasynovial in the shoulder joint?

Accepted Answer

Long head of biceps

Answer

Long head of triceps

Answer

Short head of biceps

Answer

Coracobrachialis

Question 7

Boundaries of quadrilateral space include all EXCEPT:

Accepted Answer

Deltoid

Answer

Teres major

Answer

Neck of humerus

Answer

Long head of triceps

Question 8

Olecranon process of ulna helps in formation of?

Accepted Answer

Trochlear notch

Answer

Radial notch

Answer

Olecranon fossa

Answer

Coronoid fossa

Question 9

Which muscle primarily forms the posterior wall of the axilla?

Accepted Answer

Subscapularis

Answer

Latissimus dorsi

Answer

Teres major

Answer

Pectoralis major

Question 10

What is the nerve root value of the supinator reflex (brachioradialis reflex)?

Accepted Answer

C5 C6

Answer

C3 C4

Answer

C8 T1

Answer

C4 C5

Upper Limb — MCQs

Upper Limb — MCQs

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