UL Muscles: Innervation and Actions

Nerve supply of Pectoralis major?

Medial and lateral pectoral nerves

Action of Pectoralis major?

Adducts arm and rotates it medially, clavicular fibers also flex arm

Nerve supply of Pectoralis minor?

Medial pectoral nerve

Action of Pectoralis minor?

Depresses point of shoulder, if the scapula is fixed it elevates the ribs of origin

Nerve supply of Subclavius?

Nerve to subclavius

Action of Subclavius?

Depresses the clavicle and steadies it during movements of the shoulder girdle

Nerve supply of Serratus anterior?

Long thoracic nerve

Action of Serratus anterior?

Draws scapula forward around thoracic wall, rotates scapula

Nerve supply of Trapezius?

Spinal accessory nerve (motor) and C3, C4 (sensory)

Action of Trapezius?

Upper fibers elevate scapula, middle fibers pull scapula medially, lower fibers pull medial border of scapula downward

Nerve supply of Latissimus dorsi?

Thoracodorsal nerve

Action of Latissimus dorsi?

Extends, adducts and medially rotates arm

Nerve supply of Levator scapulae?

Dorsal scapular nerve and C3, C4

Action of Levator scapulae?

Raises medial border of scapula

Nerve supply of Rhomboid minor?

Dorsal scapular nerve

Action of Rhomboid minor?

Raises medial border of scapula upward and medially

Nerve supply of Rhomboid major?

Dorsal scapular nerve

Action of Rhomboid major?

Raises medial border of scapula upward and medially

Nerve supply of Deltoid?

Axillary nerve

Action of Deltoid?

Abducts arm, anterior fibers flex and medially rotate arm, posterior fibers extend and laterally rotate arm

Nerve supply of Supraspinatus?

Suprascapular nerve

Action of Supraspinatus?

Abducts arm and stabilizes shoulder joint

Nerve supply of Infraspinatus?

Suprascapular nerve

Action of Infraspinatus?

Laterally rotates arm and stabilizes shoulder joint

Nerve supply of Teres major?

Lower subscapular nerve

Action of Teres major?

Medially rotates and adducts arm, stabilizes shoulder joint

Nerve supply of Teres minor?

Axillary nerve

Action of Teres minor?

Laterally rotates arm and stabilizes shoulder joint

Nerve supply of Subscapularis?

Upper and lower subscapular nerves

Action of Subscapularis?

Medially rotates arm and stabilizes shoulder joint

Nerve supply of Biceps brachii?

Musculocutaneous nerve

Action of Biceps brachii?

Supinates forearm and flexes elbow joint, weak flexor of shoulder joint

Nerve supply of Coracobrachialis?

Musculocutaneous nerve

Action of Coracobrachialis?

Flexes arm and is a weak adductor

Nerve supply of Brachialis?

Musculocutaneous nerve

Action of Brachialis?

Flexes elbow joint

Nerve supply of Triceps brachii?

Radial nerve

Action of Triceps brachii?

Extends elbow joint

Nerve supply of Pronator teres?

Median nerve

Action of Pronator teres?

Pronates and flexes forearm

Nerve supply of Flexor carpi radialis?

Median nerve

Action of Flexor carpi radialis?

Flexes and abducts hand at wrist joint

Nerve supply of Palmaris longus?

Median nerve

Action of Palmaris longus?

Flexes hand

Nerve supply of Flexor carpi ulnaris?

Ulnar nerve

Action of Flexor carpi ulnaris?

Flexes and adducts hand at wrist joint

Nerve supply of Flexor digitorum superficialis?

Median nerve

Action of Flexor digitorum superficialis?

Flexes middle phalanx of fingers, assists in flexing proximal phalanx and hand

Nerve supply of Flexor pollicis longus?

Anterior interosseous branch of median nerve

Action of Flexor pollicis longus?

Flexes distal phalanx of thumb

Nerve supply of Flexor digitorum profundus?

Medial half: Ulnar nerve, lateral half: Median nerve

Action of Flexor digitorum profundus?

Flexes distal phalanges of fingers, assists in flexion of middle and proximal phalanges and wrist

Nerve supply of Pronator quadratus?

Anterior interosseous branch of median nerve

Action of Pronator quadratus?

Pronates forearm

Nerve supply of Brachioradialis?

Radial nerve

Action of Brachioradialis?

Flexes forearm at elbow joint, rotates forearm to the midprone position

Nerve supply of Extensor carpi radialis longus?

Radial nerve

Action of Extensor carpi radialis longus?

Extends and abducts hand at wrist joint

Nerve supply of Extensor carpi radialis brevis?

Deep branch of radial nerve

Action of Extensor carpi radialis brevis?

Extends and abducts hand at wrist joint

Nerve supply of Extensor digitorum?

Deep branch of radial nerve

Action of Extensor digitorum?

Extends fingers and hand

Nerve supply of Extensor digiti minimi?

Deep branch of radial nerve

Action of Extensor digiti minimi?

Extends metacarpophalangeal joint of little finger

Nerve supply of Extensor carpi ulnaris?

Deep branch of radial nerve

Action of Extensor carpi ulnaris?

Extends and adducts hand at wrist joint

Nerve supply of Anconeus?

Radial nerve

Action of Anconeus?

Extends elbow joint

Nerve supply of Supinator?

Deep branch of radial nerve

Action of Supinator?

Supinates forearm

Nerve supply of Abductor pollicis longus?

Deep branch of radial nerve

Action of Abductor pollicis longus?

Abducts and extends thumb

Nerve supply of Extensor pollicis brevis?

Deep branch of radial nerve

Action of Extensor pollicis brevis?

Extends metacarpophalangeal joint of thumb

Nerve supply of Extensor pollicis longus?

Deep branch of radial nerve

Action of Extensor pollicis longus?

Extends distal phalanx of thumb

Nerve supply of Extensor indicis?

Deep branch of radial nerve

Action of Extensor indicis?

Extends metacarpophalangeal joint of index finger

Nerve supply of Palmaris brevis?

Superficial branch of ulnar nerve

Action of Palmaris brevis?

Corrugates skin to improve grip of palm

Nerve supply of Lumbricals?

1st and 2nd: Median nerve, 3rd and 4th: Deep branch of ulnar nerve

Action of Lumbricals?

Flex metacarpophalangeal joints and extend interphalangeal joints of fingers except thumb

Nerve supply of Palmar interossei?

Deep branch of ulnar nerve

Action of Palmar interossei?

Adduct fingers toward the center of the third finger

Nerve supply of Dorsal interossei?

Deep branch of ulnar nerve

Action of Dorsal interossei?

Abduct fingers from the center of the third finger, flex metacarpophalangeal joints and extend interphalangeal joints

Nerve supply of Abductor pollicis brevis?

Median nerve

Action of Abductor pollicis brevis?

Abducts thumb

Nerve supply of Flexor pollicis brevis?

Median nerve

Action of Flexor pollicis brevis?

Flexes metacarpophalangeal joint of thumb

Nerve supply of Opponens pollicis?

Median nerve

Action of Opponens pollicis?

Pulls thumb medially and forward across palm

Nerve supply of Adductor pollicis?

Deep branch of ulnar nerve

Action of Adductor pollicis?

Adducts thumb

Nerve supply of Abductor digiti minimi?

Deep branch of ulnar nerve

Action of Abductor digiti minimi?

Abducts little finger

Nerve supply of Flexor digiti minimi?

Deep branch of ulnar nerve

Action of Flexor digiti minimi?

Flexes little finger

Nerve supply of Opponens digiti minimi?

Deep branch of ulnar nerve

Action of Opponens digiti minimi?

Pulls 5th metacarpal forward as in cupping the palm