- Skeletal system
- Head muscles
- Neck muscles
- Muscles of upper limb
- Muscles of pectoral girdle
- Muscles of shoulder region
- Muscles of upper arm
- Muscles of forearm
- Muscles of hand
- Medial group (Muscles of little finger)
- Middle group of hand muscles
- Lateral group (Muscles of thumb)
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- Muscles of lower limb
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Flexor pollicis brevis
The flexor pollicis brevis (Latin: musculus flexor pollicis brevis) is a short, thin and wide muscle of the hand. Together with the adductor pollicis, abductor pollicis brevis and opponens pollicis, it forms thenar eminence on the lateral (radial) side of the palm. Therefore, the flexor pollicis brevis is also known as one of the four thenar muscles (muscles of the thumb). It lies medial to the opponens pollicis, inferior to the abductor pollicis brevis and superior to the adductor pollicis. The flexor pollicis brevis is composed of two heads - superficial and deep.
|Flexor pollicis brevis|
Superficial head - trapezium bone, flexor retinaculum
Deep head - trapezoid and capitate bones
|Insertion||Base of proximal phalanx of thumb|
Superficial head - recurrent branch of median nerve
Deep head - deep branch of ulnar nerve
|Blood supply||Superficial palmar, radialis indicis and princeps pollicis arteries|
The superficial head of the flexor pollicis brevis muscle originates from the flexor retinaculum and trapezium. The deep head originates from the trapezoid and capitate bones.
The flexor pollicis brevis inserts on the base (lateral part) of the proximal phalanx of the first finger.
The flexor pollicis brevis muscle provides the flexion of the thumb at the first carpometacarpal and metacarpophalangeal joints.
Both heads of the flexor pollicis brevis are supplied by different nerves. The superficial head is innervated by the recurrent branch of the median nerve, while the deep head is innervated by the deep branch of the ulnar nerve.
The flexor pollicis brevis muscle receives arterial blood supply from the superficial palmar, radialis indicis and princeps pollicis arteries. All are branches of the radial artery.