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Flashcards in Forearm and wrist joint Deck (20)
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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


What are the movements of the wrist

flexion, extension, abduction, adduction, circumduction (successive flexion, adduction, extension, abduction)


Which carpal bones articulate with radial styloid process in abduction and adduction

Abduction: scaphoid, lunate
Adduction: lunate, triquestrum


Draw out where muscles are in relation to inferior surface of radius and ulna

ref. notes


What problem can arise from scaphoid fracture

Branches of radial artery runs close to scaphoid so fracture->damage vessels->improper bone healing


Carpal tunnel syndrome what it involves

caused by increase in size of structures within carpal tunnel or decrease in size of carpal tunner. Inflammation of synovial sheath can also cause it.
This causes reduction in free space for median nerve causing tingling sensation and loss of coordination and strength of thumb