superficial head of flexor pollicis brevis
su·per·fi·cial head of flexor pollicis brevis[TA]
the head of the short flexor of the thumb that arises from the transverse carpal ligament (flexor retinaculum) and the trapezium. It is innervated by the recurrent branch of the median nerve.
Synonym(s): caput superficiale musculi flexoris pollicis brevis [TA]