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 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.