Intrinsic Muscles of Hand (thenar, hypothenar and short muscles)

Question 1

Opponens pollicis (thenar)

Answer 1

to oppose thumb, it draws 1st metacarpal medially to center of palm and rotates it medially
nerve supply - recurrent branch of median nerve
flexor retinaculum and tubercles of scaphnoid and trapezium -> lateral side of 1st metacarpal`

Question 2

Abuctor pollicis brevis (thenar)

Answer 2

abducts thumb; helps oppose it
nerve supply - recurrent branch of median nerve
flexor retinaculum and tubercles of scaphnoid and trapezium -> lateral side of base of proximal phalanx of thumb

Question 3

Flexor pollicis brevis: superficial head/ deep head (thenar)

Answer 3

flexes thumb
nerve supply - recurrent branch of median nerve
flexor retinaculum and tubercles of scaphnoid and trapezium -> lateral side of base of proximal phalanx

Question 4

Adductor pollics: oblique head/transverse head (thenar)

Answer 4

adducts thumb toward lateral border of palm
nerve supply - deep branch of ulnar nerve
bases of 2nd and 3rd metapcarpal, capitate, adjacent carpals -> medial side of base of proximal phalanx of 5th finger

Question 5

Abductor digiti minimi (hypothenar)

Answer 5

abducts 5th finger; assists in flexion of its proximal phalanx
nerve supply - deep branch of ulnar nerve
pisiform -> medial side of base of proximal phalanx of 5th finger

Question 6

Flexor digito minimi brevis (hypothenar)

Answer 6

flexes proximal phalanx of 5th finger
nerve supply - deep branch of ulnar nerve
hooks of hamate and flexnor retinaculum -> medial side of base of proximal phalanx of 5th finger

Question 7

Opponens digiti minimi (hypothenar)

Answer 7

draws 5th metacarpal anterior and rotates it, bringing 5th finger into oppistion with thumb
nerve supply - deep branch of ulnar nerve
hook of hamate and flexor retinaculum -> medial border of 5th metacarpal

Question 8

Lumbricals 1 and 2

Answer 8

flexes metacarpophalangeal joints; extend interphalangeal joints of 2nd-5th fingers
nerve supply - median nerve
lateral two tendons of flexor digitorum profundus (as unipennate muscles) -> lateral side of extensor expansions of 2nd-5th fingers

Question 9

Lumbricals 3 and 4

Answer 9

flex metacarpophalangeal joints; extend interphalangeal joints of 2nd-5th fingers
nerve supply - median nerve
medial three tendons of flexor digitorum profundus (as bipennate muscles) -> lateral side of extensor expansions of 2nd-5th fingers

Question 10

Dorsal interossei (1-4)

Answer 10

abduct 2nd-4th fingers from axial line; act with lumbricals in flexing metacarpophalangeal joints and extending interphalangeal joints
nerve supply - deep branch of ulnar nerve
adjacent sides of two metacarpals (as bipennate muscles) -> bases of proximal phalanges; extensor expansions of 2th-4th fingers

Question 11

Palmar interossei, 1-3

Answer 11

adduct 2nd, 4th, and 5th fingers toward axial line; assist lumbricals in flexing metacarpophalageal joints and extending interphalangeal joints
nerve supply - deep branch of ulnar nerve
palmar surfaces of 2nd, 4th and 5th metacarpals (as unipennate muscles) -> bases of proximal phalanges; extensor expansions of 2nd, 4th and 5th fingers