Hand Muscles - Thenar

Question 1

opponens pollicis

Answer 1

PA:
+ flexor retinaculum
+ tubercles of scaphoid and trapezium

DA:
+ lateral side of 1st metacarpal

N:
+ recurrent branch of median nerve (C8*, T1)

A:
+ draws first metacarpal medially to center of palm and rotates it medially to oppose thumb

Question 2

abductor pollicis brevis

Answer 2

PA:
+ flexor retinaculum
+ tubercles of scaphoid and trapezium

DA:
+ lateral side of base of proximal phalanx and thumb

N:
+ recurrent branch of median nerve (C8*, T1)

A:
+ abducts thumb; helps oppose it

Question 3

flexor pollicis brevis (superficial head and deep head)

Answer 3

PA:
+ flexor retinaculum
+ tubercles of scaphoid and trapezium

DA:
+ lateral side of base of proximal phalanx and thumb

N:
+ recurrent branch of median nerve (C8*, T1)

A:
+ flexes thumb

Question 4

adductor pollicis (oblique head and transverse head)

Answer 4

PA:
+ oblique head: bases of 2nd and 3rd metacarpals
+ capitate
+ adjacent carpals
+ transverse head: anterior surface of shaft of 3rd metacarpal

DA:
+ medial side of base of proximal phalanx of the thumb

N:
+ deep branch of the ulnar nerve (C8, T1*)

A:
+ adducts thumb toward lateral border of thumb