Hand Anatomy Quiz

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Questions and Answers

Which muscle is NOT part of the thenar eminence?

Flexor digiti minimi (correct)

Opponens pollicis

Adductor pollicis

Abductor pollicis brevis

What is the primary nerve supply for the muscles of the hypothenar eminence?

Radial nerve

Ulnar nerve (correct)

Musculocutaneous nerve

Median nerve

Which muscle in the hand is responsible for performing abduction of the little finger?

Opponens digiti minimi

Abductor digiti minimi (correct)

Flexor digiti minimi

Palmaris brevis

Which action do the dorsal interossei muscles perform?

Abduction at the MCP joints Signup and view all the answers

What is the origin of the lumbricals in the hand?

Tendon of flexor digitorum profundus Signup and view all the answers

Which muscle action is primarily associated with the adductor pollicis?

Adduction of the thumb Signup and view all the answers

Which of the following statements about the palmaris brevis is true?

It helps in gripping by making hypothenar eminence prominent. Signup and view all the answers

What is the primary action of the interossei muscles?

Abducting and adducting the fingers Signup and view all the answers

Which nerve supplies the anterior compartment of the arm muscles such as the brachialis and biceps?

Musculocutaneous nerve Signup and view all the answers

What area does the superficial branch of the radial nerve supply?

Lateral 2/3 of the dorsal surface of the hand Signup and view all the answers

Which nerve emerges between the two heads of the supinator muscle?

Posterior interosseous nerve Signup and view all the answers

Which condition is associated with the injury of the radial nerve leading to the inability to extend the wrist?

Wrist drop Signup and view all the answers

Which branch of the radial nerve supplies the skin of the back of the forearm?

Posterior cutaneous nerve of forearm Signup and view all the answers

Which nerve is responsible for carrying sensation from the skin over the deltoid muscle?

Axillary nerve Signup and view all the answers

In which anatomical region does the median nerve first appear during its course?

Arm Signup and view all the answers

What is the significance of the palmar cutaneous branch of the median nerve?

It is not affected in carpal tunnel syndrome. Signup and view all the answers

Which of the following statements about the ulnar nerve's location is accurate?

It lies medial to the axillary artery. Signup and view all the answers

At what anatomical position is the ulnar nerve particularly vulnerable to injury?

Superficial to the flexor retinaculum Signup and view all the answers

Which muscles receive a muscular branch from the median nerve in the forearm?

Flexor carpi radialis Signup and view all the answers

Which of the following branches does NOT arise from the ulnar nerve?

Anterior interosseous nerve Signup and view all the answers

What area of the hand does the palmar digital branches of the median nerve supply?

Lateral 3 ½ fingers Signup and view all the answers

Study Notes

Hand Anatomy

The hand's objective is to identify thenar and hypothenar eminences, and to describe the movements and nerve supply of hand muscles.
Muscles of the thumb comprise the thenar eminence, while the little finger's muscles form the hypothenar eminence.
Lumbricals and interossei are also hand muscles.
Thenar eminence muscles include abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, and adductor pollicis.
Hypothenar eminence muscles comprise abductor digiti minimi, flexor digiti minimi, opponens digiti minimi, and palmaris brevis.
Thumb movements include abduction, adduction, extension, flexion, and opposition. Abduction and adduction are perpendicular to the other four fingers, and extension and flexion are parallel.
Lumbricals are small muscles originating from the flexor digitorum profundus tendon. Their nerve supply varies: the first two receive median nerves, and the last two receive ulnar nerves. Their action is flexion at the MCP joint and extension at the interphalangeal joints.
Interossei (dorsal and palmar) muscles lie between metacarpal bones. The ulnar nerve supplies them. Their action is PAD (palmar adduction, dorsal abduction). The dorsal interossei are bipinnate.
Palmaris brevis is a superficial muscle under the skin, whose ulnar nerve supply helps with gripping. It also improves hand grip by making the hypothenar eminence prominent.

Nerve Injuries - Upper Limb

Brachial plexus injuries include Erb palsy ("waiter's tip") and Klumpke palsy.
- Erb palsy is associated with traction/tear of upper trunk (C5-C6 roots).
- Klumpke palsy is linked to traction/tear of lower trunk (C8-T1 roots).
Musculocutaneous nerve originates from the lateral cord (C5,6,7). It passes between biceps brachii and brachialis muscles and supplies coracobrachialis, biceps, and brachialis muscles and skin of the lateral forearm.
Axillary nerve originates from posterior cord of the brachial plexus, exits the axilla, innervates deltoid and teres minor muscles, and supplies sensation to skin over the deltoid muscle.
Median nerve is lateral to the axillary artery and anterior to the elbow joint. It passes between the pronator teres heads, the deep surface of flexor digitorum superficialis, enters the palm through the carpal tunnel, and is deep to the flexor retinaculum.
Median nerve branches in the forearm supply pronator teres, flexor carpi radialis, palmaris longus, and flexor digitorum superficialis, and have articular branches for the elbow joint.
- Palmar cutaneous branch supplies the lateral 2/3 of palm skin, isn't affected by carpal tunnel syndrome.
Ulnar nerve is medial to the axillary artery and passes posterior to the medial epicondyle of the humerus. In the forearm, it passes between the flexor carpi ulnaris heads. It passes between flexor carpi ulnaris and flexor digitorum profundus muscles at the wrist. Ulnar nerve branches in the forearm supply flexor carpi ulnaris and the medial half of flexor digitorum profundus. The palmar branch supplies medial palm skin, and the dorsal branch supplies medial dorsal hand and 1 1/2 medial fingers skin. Superficial branch supplies palmaris brevis and the medial 11/2 skin of the palm. The deep branch supplies interossei, adductor pollicis, and the first two lumbricals.
Radial nerve originates in the lower triangular space, accompanies profunda brachii artery. It crosses the radial groove medially to laterally. It appears in the forearm between the brachialis and brachioradialis muscles. It divides into deep and superficial branches. The superficial branch supplies skin of lateral 2/3 of the dorsal hand and the skin of lateral 3 ½ fingers, except the distal phalanges. Deep branches supply brachialis, triceps, anconeus, brachioradialis, and extensor carpi radialis longus.

Additional information

References are provided for further research.

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Description

Test your knowledge on hand anatomy! This quiz focuses on identifying the thenar and hypothenar eminences, the muscles involved, and the movements of the thumb. Explore the intricacies of hand muscles and their nerve supplies.