Muscles of the hand - to supplement 'muscles of the hand in ESA2'

Question 1

List the extrinsic flexors of the hand and their actions

Answer 1

Flexor digitorium superficialis - flexion of the fingers at the MP joint
Flexor digitorium profundus - flexion at the MP & IP joints
Flexor pollicis longus - flexes phalanges of 1st digit (thumb)

Question 2

List the extrinsic extensors of the hand & their actions

Answer 2

Extensor digitorium
Extensor digiti minimi
Extensor pollicis brevis & EP longus
Abductor pollici longus

Question 3

How do extensor pollicis brevis and longus differ in their actions?

Answer 3

brevis extends thumb at CM & MP joints

longus extends thumb at CM, MP & IP joints

Question 4

Where do the lumbricals arise from?

Answer 4

(4) From one or both of the side of adjoining flexor digitorium profundus tendons

Question 5

Action of the dorsal interossei (1st-4th)?

Answer 5

Abduct 2nd-4th digits from axial line

Question 6

Action of palmer interossei (1st - 3rd)

Answer 6

Adduct 2nd, 4th & 5th digits

Question 7

Action of the lumbricals?

Answer 7

Reinforce action of interossei by extending the IP joints and assist in radial deviation of the MP joint