Muscles of the Anterior Forearm

Question 1

Superficial muscles

Answer 1

Pronator teres (pass)
Flexor carpi radialis (fail)
Palmaris longus (pass)
Flexor carpi ulnaris (fail)

Question 2

Pronator teres

Answer 2

Origin - medial epicondyle and coronoid process of ulna
Attachment - laterally to the mid-shaft of radius
Action - pronation of forearm
Innervation - median nerve

Question 3

Flexor carpi radialis

Answer 3

Origin - medial epicondyle
Attachment - base of metacarpals I and II
Action - flexion and abduction of the wrist
Innervation - median nerve

Question 4

Palmaris longus

Answer 4

Origin - medial epicondyle 
Attachment - flexor retinaculum of the wrist 
Action - flexion at the wrist 
Innervation - median nerve 
(Absent in around 15% of population)

Question 5

Flexor carpi ulnaris

Answer 5

Origin - medial epicondyle and ulna
Attachment - pisiform carpal bone
Action - flexion and adduction at the wrist
Innervation - ulnar nerve

Question 6

Intermediate muscles

Answer 6

Flexor digitorum superficialis

Question 7

Flexor digitorum superficialis

Answer 7

Origin - medial epicondyle of humerus and the radius
Attachment - 4 tendons attach to middle phalanges of four fingers
Action - flexes the metacarpophalangeal joints and proximal interphalangeal joints at 4 fingers and flexes at the wrist
Innervation - median nerve

Question 8

Deep muscles

Answer 8

Flexor digitorum profundus, flexor pollicis longus, pronator quadratus

Question 9

Flexor digitorum profundus

Answer 9

Origin - ulna and associated interosseous membrane
Attachment - distal phalanges of four fingers
Action - flexes the distal interphalangeal joints of fingers, also flexes at metacarpophalangeal joint and wrist
Innervation - medial half (acts on little and ring fingers) - ulnar nerve
Innervation - lateral half (acts on middle and index fingers) - anterior interosseous branch of median nerve

Question 10

Flexor pollicis longus

Answer 10

Origin - anterior surface of radius and surrounding interosseous membrane
Attachment - base of distal phalanx of thumb
Action - flexes the interphalangeal joint and metacarpophalangeal joint in thumb
Innervation - anterior interosseous branch of median nerve

Question 11

Pronator quadratus

Answer 11

Origin - anterior surface of ulna
Attachment - anterior surface of radius
Action - pronates the forearm
Innervation - anterior interosseous branch of the median nerve