Muscles of the Upper Limb Flashcards
Innervation of pectoralis major
Medial pectoral nerve
Lateral pectoral nerve
Origins in C7, C8 and T1 to the lower trunk of the brachial plexus
Describe the function of the pectoralis major.
Medial rotation of the arm
Function of the deltoid
Anterior fibres - flexion of the arm (clavicular)
Middle fibres - abduction from 15-90 degrees (acromial)
Posterior fibres - extention (spinal)
Innervation of the deltoid
Axillary nerve from the ventral rami of C5 and C6 to the posterior cord of the brachial plexus
Function of pectoralis minor
Stabalises the scapula by drawing it inferiorly and anteriorly
Innervation of the pectoralis minor
Medial pectoral nerve (C8, T1)
Function of the subclavius
Depresses the clavicle
Can protect underlying structures if the clavicle is fractured
Innervation of the subclavius
Nerve to subclavius
Function of the serratus anterior
Abduction of the scapula to assist the deltoid in abducting the arm.
Innervation of the serratus anterior
Long thoracic nerve from roots C5,6,7 of the brachial plexus
Innervation of the extensor carpi ulnaris
Posterior interosseus nerve (deep branch of the radial nerve)
Function of extensor carpi ulnaris
Extends and adducts the wrist
Innervation of extensor digiti minimi
Posterior interosseus nerve (deep branch of the radial nerve)
Function of extensor digiti minimi
Extends the little finger
Innervation of extensor digitorum
Posterior interosseus nerve (deep branch of the radial nerve)
Function of extensor digitorum
Extends the four fingers and the wrist
Function of the aconeus
Abduction of the ulna
Accessory extension at the elbow
Innervation of the aconeus
Radial nerve
Function of extensor carpi radialis longus
Extend and abduct the wrist
Innervation of extensor carpi radialis longus
Radial nerve
Function of extensor carpi radialis brevis
Extend and abduct the wrist
Innervation of extensor carpi radialis brevis
Deep branch of the radial nerve`
Function of extensor pollicus longus
Extends all joints of the thumb
Innervation of extensor pollicus longus
Posterior interosseus nerve (deep branch of the radial nerve)
Function of extensor indices
Extends the index finger
Innervation of extensor indices
Posterior interosseus nerve (deep branch of the radial nerve)
Function of supinator
Supination of the forearm
Innervation of the supinator
Posterior interosseus nerve (deep branch of the radial nerve)
Function of the abductor pollicus longus
Accessory extensor of the thumb for abduction
Innervation of abductor pollicus longus
Posterior interosseus nerve (deep branch of the radial nerve)
Function of extensor pollicus brevis
Extends the metacarpophalangeal/carpometacarpal joints
Innervation of extensor pollicus brevis
Posterior interosseus nerve (deep branch of the radial nerve)
What is the extensor retinaculum?
The aponeurosis across the back of the wrist which covers and acts as an insertion point for extensor muscles of the forearm.
Function of opponens pollicis
Oppose the thumb by rotating and flexing at the metacarpophalangeal joint.
Innervation of opponens pollicis
Median nerve
Function of abductor pollicis brevis
Abducts the thumb
Innervation of abductor pollicis brevis
Median nerve
Function of flexor pollicis brevis
Flexes the metacarpophalangeal joint of the thumb
Innervation of flexor pollicis brevis
Median nerve
Function of opponens digiti minimi
Rotates the metacarpal of the little finger towards the thumb for opposition
Innervation of opponens digiti minimi
Ulnar nerve
Function of abductor digiti minimi
Abducts the little finger
Innervation of abductor digiti minimi
Ulnar nerve
Function of flexor digiti minimi brevis
Flexes the little finger
Innervation of flexor digiti minimi brevis
Ulnar nerve
Function of the lumbricles
Flex at the metacarpophalangeal joint and extend at the interphalangeal joint
Innervation of the lumbricles
Medial two by the ulnar nerve
Lateral two by the median nerve
How many dorsal interossei muscles are there?
4
Function of the dorsal interossei
Abduct the fingers at the metacarpophalangeal joint
Innervation of dorsal interossei
Ulnar nerve
How many palmar interossei muscles are there?
3
Function of the palmar interossei
Adduct the fingers at the metacarpophalangeal joint
Innervation of the palmar interossei
Ulnar nerve
Function of palmaris brevis
Deepens the curvature of the hand, improving grip
Innervation of palmaris brevis
Ulnar nerve
Function of adductor pollicis
Adduct the thumb
Innervation of adductor pollicis
Ulnar nerve
What are the two muscles in the palm of the hand?
Palmaris brevis
Adductor pollicis
What are the muscles of the thenar eminence?
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
What are the muscles of the hypothenar eminence?
Opponens digiti minimi
Abductor digiti minimi
Flexor digiti minimi brevis