Forearm and wrist joint Flashcards
In the posterior compartment of forearm, where are the common insertions and where are the muscle innervaations
insertion on lateral epicondyle
muscle innervation from radial n.
Contains key muscles that extend the hand and the digits
List and label the superficial and deep muscles of the posterior forearm
Superficial: extensor digitorum (to all 4 fingers not thumb), extensor digiti minimi (to 5th digit), extensor carpi ulnaris (to base of 5th metacarpal)
Deep: supinator, abductor policis longus, extensor policis longus, extensor policis brevis, extensor indicis
supinator, extensor carpi radialis longus, extensor carpi radialis brevis
What is the anatomical snuffbox bounded by and what’s in it
Borders: medial=extensor policis longus, lateral=extensor policis brevis, floor=scaphoid and trapezium, proximal=styloid process of radius
Content: radial artery, superficial branch of radial nerve, cephalic vein
What is the mobile wad and what is it comprised of
A group of muscles which move during pronation and supination. Its functions change when their positions change so even though posterior extensors, sometimes act as minimal flexors
Extensor carpi radialis longus and extensor carpi radialiss brevis are both weak flexors at elbow joint.
Brevis=moves arm from ulnar abduction to its midd position and flexes dorsally.
longus=weak pronator in flexed arm and supinator in outstretched arm
Brachioradialis brings forearm into mid position between pronation and supination and acts as flexor at this point
What route does the radial nerve take for innervation
Passes through elbow in anterior compartment then descends lateral and posterior into poisterior forearm-posterior interosseous
What does the posterior interosseous artery supply
superficial and deep extensors
What is the anterior forearm muscles innervated by and what are its main arteries
Innevation: median nerve, some ulnar nerve
Main arteries: ulnar and radial
What are the 5 common anterior forearm muscles and how are they arranged
flexor carpi ulnaris, palmaris longus, flexor carpi radialis, pronator teres top layer, (flexor digitorum superficialis 2nd layer) Common origin from medial epicondyle of humerus
NB 3rd layer=flexor pollicis longus, flexor digitorum profundis, 4th layer pronator quadratus
Neurovasculature of forearm
The median nerve lies between flexor carpi radialis and palmaris longus
Ulnar nervve and artery lie to radial side of flexor carpi ulnaris
Carpal tunnel what is it formed by, what passes through it and what doesn’t pass through it
scaphoid and trapezium tubercles laterally, hook of hamate and pisiform medially, superficial flexor retinaculum forms arch
Median nerver passes through with tendon of flexxor digitorum profundus and superficialis
Ulnar nerve and artery doesn’t go through carpal tunnel, it goes through guyon canal between pisiform and hook of hamate
What are the deep muscles of the anterior compartment
flexxor digitorum profundus, flexor policis longus, pronator quadratus
What are the roots of the median nerve and what does it innervate
C4-T2 root
pronator teres, flexor carpi radialis, palmaris longus, flexor digitorum profundis, lumbricals, thenar muscles, pronator quadratus, flexor policis longus
What are the roots of the ulnar nerve and what does it innervate
C8-T1 root
Flexor carpi ulnaris, flexor digitorum profundis, palmaris brevis, hypothenar muscles, lumbricals, palmar interosseei, adductor policis, dorsal interosssei
Sketch the main arteries and veins forearm anterior compartment
ref. notes
What are the 2 wrist joints
Radiocarpal joint, midcarpal joint
NB ulna not involved in joint
