deep head of flexor pollicis brevis

deep head of flex·or pol·li·cis bre·vis

[TA]
the head of short flexor of the thumb that arises from the trapezoid and capitate bones and transverse carpal ligaments. It is innervated by the deep ulnar nerve, and considered by many to be the first palmar interosseous muscle.
References in periodicals archive ?
The deep head of flexor pollicis brevis showed a different find: In 52 (65%) limbs a double innervation occurred (Fig.
The deep head of flexor pollicis brevis was absent in 11 hands (14%), in 52 hands (65%), occurred a double innervation, in 14 (17.5%) exclusively by deep branch of ulnar nerve and 3 (3.6%) exclusively by a branch of median nerve.
The deep ulnar nerve is responsible for motor control of intrinsic hand function through innervation of the dorsal and palmar interossei, the lumbricals of fourth and fifth digits, the hypothenar muscles (abductor, flexor and opponens digiti minimi), adductor pollicis muscle and the deep head of flexor pollicis brevis. (6) The superficial ulnar nerve supplies sensation over the hypothenar eminence and through two common palmar digital nerves over the palmar aspect of the fifth finger and the adjacent sides of the fourth and fifth fingers.