Flexor pollicis brevis muscle
|Flexor pollicis brevis muscle|
Superficial muscles of the left hand, palmar view.
|Origin||trapezium, flexor retinaculum|
|Insertion||thumb, proximal phalanx|
|Artery||Superficial palmar arch|
|Nerve||Recurrent branch of the median nerve, deep branch of ulnar nerve (medial head)|
|Actions||Flexes the thumb at the first metacarpophalangeal joint|
|Antagonist||Extensor pollicis longus and brevis|
|Latin||musculus flexor pollicis brevis|
|Anatomical terms of muscle|
The flexor pollicis brevis is a muscle in the hand that flexes the thumb. It is one of three thenar muscles. It has both a superficial part and a deep part.
Origin and insertion
The muscle's superficial head arises from the distal edge of the flexor retinaculum and the tubercle of the trapezium, the most lateral bone in the distal row of carpal bones. It passes along the radial side of the tendon of the flexor pollicis longus.
The deeper (and medial) head "varies in size and may be absent." It arises from the trapezoid and capitate bones on the floor of the carpal tunnel, as well as the ligaments of the distal carpal row.
The flexor pollicis brevis receives its blood supply from the superficial palmar branches of radial artery.