Posterior Forearm And Dorsum Of Hand Flashcards
What are the muscles acting at the wrist joint
Extensor carpi Ulnaris
Extensor carpi radialis longus
Extensor carpi radialis brevis
What is the origin, insertion, innervation and unction of extensor carpi ulnaris?
Origin: Lateral epicondyle of humerus and posterior border of ulnar
Insertion: Tubercle on the base of medial side metacarpal V
Posterior interosseous nerve C7,C8
What is the origin, insertion, innervation and unction of extensor carpi radialis longus?
Origin: Distal pat of lateral Supraepicondylar ridge of humerus and inter muscular septum
Insertion: Dorsal surface o base of metacarpal II
Innervation- Radial nerve- C5,C6) before division into superficial and deep branches
Unction - extends and abducts wrist
State the origin, insertion, innervation and action of extensor indicis
o = posterior surface of the ulnar and adjacent interosseous membrane
i = extensor hood of index
i = posterior interosseous nerve
extends the index finger
State the origin, insertion, innervation and action of abductor pollicis longus
o = posterior ulna and radius - distally to the supinator and anconeus muscle
i = lateral base of MC 1
posterior interosseous nerve
abducts the carpometacarpal joint of MC 1
State the origin, insertion, innervation and action of extensor pollicis brevis
o = posterior radius, distal to the APL
i = dorsal base of proximal phalanx of the thumb
posterior interosseous nerve abducts
extends the MC+CMC thumb joint
State the origin, insertion, innervation and action of the supinator muscle
o = superiorly = the lateral epicondyle, radial collateral and anulnar ligament. distally = supinator crest of the ulna
i = lateral radius superior to anterior oblique line
posterior interosseous nerve
supination
Which interossei muscles are responsible for abduction/adduction and how many are there of each
anteriorly = palmar = 3 = adducts
posteriorly = dorsal = 4 = abducts
Which fingers of the hand have 2 tendons rather than 1
the little finger and index finger
Which muscle flexes the proximal first two phalanges of the finger
the flexor digitorum superficialis
Which muscle flexes all three phalanges of the finger
flexor digitorum profundus
What is the role of the lumbrical muscle
pulls on the extensor tendon expansion to flex at the MC joint and straighten the finger
Which muscle extends the finger again after the lumbrical muscle has acted
extensor digitorum
What artery passes through the anatomical snuffbox?
Radially artery- passes obliquely deep to extensor tendons passing into of thumb and lies adjacent to scaphoid trapezium
What is the lateral, medial border and floor of the anatomical snuffbox?
Lateral border- formed by tendons of the abductor pollicis longus amd longus and extensor pollicis brevis
Medial border- formed by the tendon of the extensor pollicis longus
Floor- scaphoid and trapezium and distal ends of tendons of extensor carpi radilias long and extensor carpi radial is brevis
What is the anatomical snuffbox?
A term given to a triangular depression formed on the posterolateral side of the wrist and metacarpal I by the extensor tendons passing into the thumb
What is the origin, insertion, innervation and function of extensor digiti minimi?
Lateral epicondyle of humerus and adjacent inter muscular septum together with extensor digitrum
Insertion: extensor hood of the little finger
Posterior interosseous nerve C7,C8
Function - Extend the fifth digit at its metacarpophalangeal joint
What is the origin, insertion, innervation and function of extensor carpi digitorum
Origin: Lateral epicondyle of humerus and adjacent inter muscular septum and deep fascia
Insertion: Four tendons which insert via extensor hoods into dorsal aspects of the bases of the middle and distal phalanges of the index, middle, ring and little finge finger
Innervation- posterior interosseous C7,C8
Function- Extends the index, middle ring and little finger- also extend wrist
What is the origin, insertion, innervation and unction of brachioradialis?
Brachioradialis-
Origin- proximal part of lateral suprepicondylar ridge of humerus and adjacent inter muscular septum
Insertion- lateral surface of distal end of radius
Innervation- radial nerve C5,C6 before division into superficial and deep branches
Function- Accessory flexor o elbow joint when forearm is midpronated
What muscles act upon the thumb?
Extensor pollicis longus, Extensor indicis, abductor pollicis longus
Extensor pollicis brevis
What is the origin, insertion, innervation and function of extensor carpi radialis brevis?
Origin: lateral epicondyle of humerus and adjacent inter muscular septum
Insertion: dORSAL SURFACE of metacarpals II and III
Innervation- radial nerve/ interosseous nerve
Function- To extend and abduct wrist
What muscles extend the 4 medial fingers?
Extensor digiti minimi, extensor digitorum,extensor indics
What are the muscle of the superficial layer of the posterior forearm?
Brachioradialis, Extensor carpi radialis longus,
Extensor carpi radialis brevis,
Extensor digitorum
Extensor carpi ulnaris
State the origin, insertion, innervation and action of extensor pollicus longus
o = posterior surface of the ulnar, distally to the APL
i = dorsal base of distal phalanx of thumb
i = posterior interosseous nerve
extends the interphalangeal, carpometacarpal and metacarpal thumb joint
What muscles form the deep layer of the posterior forearm
extensor pollicus longus
extensor indicis
supination
abductor pollicis longus
extensor pollicis brevis
What are the superficial muscles of the posterior forearm
extensor digitorum
extensor carpi ulnaris
extensor carpi radialis longus and brevis
