Muscles of the Upper Limb

Question 1

What are the muscles of the upper arm

Answer 1

Biceps brachii

Coracobrachialis

Brachialis

Triceps brachii

Question 2

What are the innervations and actions of the anterior muscles of the upper arm

Answer 2

Biceps brachii - musculocutaneous nerve, actions: supination of forearm, flexion of arm at elbow and at shoulder

Coracobrachialis - musculocutaneous nerve, actions: flexion of arm and shoulder, weak adduction

Brachilais - musculocutaneous nerve, flexion at elbow

Question 3

What is the innervation and action of the muscles in the posterior compartment of the upper arm

Answer 3

Triceps brachii - radial nerve, extension of the arm at the elbow

Question 4

What are the muscles in the anterior compartment of the forearm

Answer 4

Flexor carpi ulnaris

Flexor carpi radialis

Palmaris longus

Pronator teres

Flexor digitorum profundus

Flexor digitorum superficialis

Flexor pollicis longus

Pronator quadratus

Question 5

What are the innervation and actions of the muscles in the superficial anterior compartment of the forearm

Answer 5

Flexor carpi ulnaris - flexion and adduction at wrist, ulnar nerve

Palmaris longus - flexion at wrist, median nerve

Flexor carpi radialis - flexion and abduction at wrist, median nerve

Pronator teres - pronation of forearm, median nerve

Question 6

What are the innervations and actions of the muscles of the intermediate anterior compartment of the forearm

Answer 6

Flexor digitorum superficialis - fexes metacarpophalangeal joints and proximal interphalangeal joints at four fingers and flexes at wrist, median nerve

Question 7

What are the innervations and actions of the muscles in the deep anterior compartment of the forearm

Answer 7

Flexor digitorum profundus - flexes distal interphalangeal joints and metacarpophalangeal joints of fingers and flexes at wrist, medial half by ulnar, lateral half by anterior interosseous branch of median

Flexor pollicis longus - flexes interphalangeal joint and metacarpophalangeal joint of thumb, anterior interosseous branch of median

Pronator quadratus - pronates forearm, anterior interosseous branch of median

Question 8

What are the muscles in the posterior forearm

Answer 8

Brachioradialis

Extensor carpi radialis longus and brevis

Extensor digitorum

Extensor digiti minimi

Extensor carpi ulnaris

Anconeus

Supinator

Abductor pollicis longus

Extensor pollicis brevis

Extensor pollicis longus

Extensor indicis proprius

Question 9

What is the innervation and what are the actions of the superificial posterior forearm muscles

Answer 9

Radial Nerve

Brachioradialis - flexes at elbow

Extensor carpi radialis longus and brevis - extends and abducts the wrist

Extensor digitorum - extends medial four fingers at MCP and IP joints

Extensor digiti minmi - extends little finger and contributes to wrist extension

Extensor carpi ulnaris - extension and abduction of wrist

Anconeus - extends and stabilises elbow joint and abducts the ulna during pronation

Question 10

What is the innervation and what are the actions of the deep posterior forearm muscles

Answer 10

Radial nerve

Supinator - supinates the forearm

Abductor pollicis longus - abducts the thumb

Extensor pollicis brevis - extends at metacarpophalangeal joint and carpometacarpal joint of the thumb

Extensor pollicis longus - extends at all thumb joints

Extensor incidis proprius - extends index finger