Upper Limb II: The Arm and Forearm Flashcards
(24 cards)
Biceps brachii
- Action: Supinates forearm, when supine will flex forearm; resists dislocation of shoulder (short head)
- Blood supply: Brachial artery
- Innervation: Musculocutaneous nerve (C5, C6)
Coracobrachialis
- Action: Flexes and adducts arm at shoulder joint; resists dislocation of shoulder joint
- Blood supply: Brachial artery
- Innervation: Musculocutaneous nerve
Brachialis
- Action: Flexes forearm at elbow
- Bloody supply: Brachial artery
- Innervation: Musculocutaneous nerve (C5, C6), lateral portions may receive radial nerve contributions
Anconeus
- Action: Assists triceps in extension of forearm and stabilizes elbow joint; also abducts ulna during pronation
- Blood supply: Deep brachial artery
- Innervation: Radial nerve (C7, C8, T1)
Triceps brachii
- Action: Extends forearm at elbow joint (main); resists dislocation of shoulder joint (long head)
- Blood supply: Deep brachial artery
- Innervation: Radial nerve (C6, C7, C8)
Pronator teres
- Action: Pronates and flexes forearm at elbow
- Innervation: Median nerve
Flexor carpi radialis
- Action: Flexes and abducts hand at wrist
- Innervation: Median nerve
Palmaris longus
- Action: Flexes hand at wrist, tenses palmar aponeurosis
- Innervation: Median nerve
Flexor carpi ulnaris
- Action: Flexes and adducts hand at wrist
- Innervation: Ulnar nerve
Flexor digitorum superficialis
- Action: Flexes middle phalanges at proximal interphalangeal joint, flexes proximal phalanges at metacarpophalangeal joints
- Innervation: Median nerve
Flexor digitorum profundus
- Action: Flexes distal phalanges at interphalangeal joints (power grip)
- Innervation: Median and ulnar nerves
Flexor pollicis longus
- Action: Flexes thumb
- Innervation: Median nerve via anterior interosseous nerve (branch of medial nerve)
Pronator quadratus
- Action: Pronates forearm, deep fibers bind radius and ulna together
- Innervation: Median nerve via anterior interosseous nerve
Brachioradialis
- Action: Flexes forearm when it is pronated (about midprone position)
- Innervation: Radial nerve
Extensor carpi radialis longus
- Action: Extend and abduct hand at wrist
- Innervation: Radial nerve
Extensor carpi radialis brevis
- Action: Extend and abduct hand at wrist
- Innervation: Deep branches of radial nerve
Extensor digitorum
- Action: Extends medial 4 fingers at metacarpophalangeal joints and somewhat at interphalangeal joints
- Innervation: Posterior interosseous nerve
Extensor digiti minimi
- Action: Extends 5th finger at metacarpophalangeal joint and secondarily at interphalangeal joints
- Innervation: Posterior interosseous nerve
Extensor carpi ulnaris
- Action: Extends and adducts hand at wrist
- Innervation: Posterior interosseous nerve
Supinator
- Action: Supinates forearm, bringing radius back to anatomical position
- Innervation: Deep branch of radial nerve
Extensor indicis
- Action: Independent extension of 2nd finger, but also helps with extension of wrist
- Innervation: Posterior interosseous nerve (this nerve is the continuation of the deep branch of the radial nerve)
Abductor pollicis longus
- Action: Abducts thumb and extends it at carpometacarpal joint
- Innervation: Posterior interosseous nerve (this nerve is the continuation of the deep branch of the radial nerve)
Extensor pollicis brevis
- Action: Extends proximal phalanx of thumb at its metacarpophalangeal joint, also extends carpometacarpal joint
- Innervation: Posterior interosseous nerve
Extensor pollicis longus
- Action: Extends distal phalanx of thumb at its interohalangeal and carpometacarpal joint
- Innervation: Posterior interosseous nerve
