Forearm Flashcards
Anterior compartment of forearm
3 layers
Superficial intermediate and deep
Superficial layer of anterior compartment of forearm
Flexor carpi ulnaris
Palmaris longus
Flexor carpi radialis
Pronator teres
Flexor carpi ulnaris
Most medial
Origin: medial epicondyle (humeral head) and olecranon (ulnar head)
Insertion: Distal fibre attaches to pisiform bone
Ulnar nerve passes through triangular gap between humeral and ulnar heads of flexor carpi ulnaris
Palmaris longus
Origin: medial epicondyle
Insertion: palmar aponeurosis of hand
Flexor carpi radialis
Origin: medial epicondyle
Insertion: base of metacarpals II and III
Pronator teres
Origin: medial epicondyle
Insertion: roughening on lateral surface of radius
Median nerve passes through ulnar and humeral head of this muscle
Intermediate layer - flexor digitorum superficialis
Two heads
Origin: humero-ulnar head - medial epicondyle
Radial head - anterior oblique line of radius
Median nerve and ulnar artery passes deep to FDS between the two heads
Tendons of ring and middle finger are superficial to index and little finger. Tendons of FDS are anterior to tendons of FDP
Flex PIP, MCP and wrist joint
Deep muscles of anterior compartment
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
Flexor digitorum profundus
Origin: anterior and medial surface of ulna + interosseous membrane
Insertion: distal phalanx
Innervation: lateral half (anterior interosseous - branch of median nerve) medial half (ulnar nerve)
Flexes MCP, DIP and PIP + wrist
In the palm, lumbricals originate from sides of tendons of FDP.
Flexor pollicis longus
Origin: anterior surface of radius
Insertion: palmar surface of base of distal phalanx of thumb
Innervation: Anterior interosseous nerve (median)
Flexes MCP and IP joint of thumb
Pronator quadratus
Origin: linear ridge on distal anterior surface of ulna
Insertion: distal anterior surface of radius
Innervation: anterior interosseous nerve (median)
Pronate forearm
Radial artery
Passes along lateral aspect of forearm:
- Just deep to brachioradialis in proximal half of forearm
- Superficial branch of radial nerve is lateral to it in middle third of forearm
- Tendon of brachioradialis is lateral to it in the distal forearm
Leaves the forearm by passing around lateral side of wrist and penetrates posterolateral aspect of hand between bases of metacarpals I and II.
Branches of radial artery
Radial recurrent artery - elbow joint + muscles on lateral side of forearm
Palmar carpal branch - carpal bones and joints
Superficial palmar branch - passes superficial to thenar muscles at base of thumb to enter hand
Ulnar artery
Larger than radial artery, medial side of forearm
Leaves cubital fossa by passing deep to pronater teres muscle, then passes through forearm between FCU and FDP
Distal forearm - ulnar nerve is medial to ulnar artery, with FCU most medial
Enters hand by passing lateral to pisiform bone and superficial to flexor retinaculum and arches over palm
Branches of ulnar artery
Ulnar recurrent artery for elbow joint
Common interosseous artery - divides into anterior and posterior - for muscles
Dorsal and palmar carpal branches for wrist