Extensor pollicis brevis

Extensor pollicis brevis muscle
Front of right upper extremity. (Extensor pollicis brevis labeled at upper left.)
Posterior surface of the forearm. Deep muscles. (Extensor pollicis brevis visible at left.)
Details
Origin	radius and the interosseous membrane
Insertion	thumb, proximal phalanx
Artery	posterior interosseous artery
Nerve	posterior interosseous nerve
Actions	extension of thumb at metacarpophalangeal joint
Antagonist	Flexor pollicis longus muscle, Flexor pollicis brevis muscle
Identifiers
Latin	musculus extensor pollicis brevis
Dorlands /Elsevier	m_22/12548946
TA	A04.6.02.050
FMA	38518
Anatomical terms of muscle []

In human anatomy, the extensor pollicis brevis is a skeletal muscle on the dorsal side of the forearm. It lies on the medial side of, and is closely connected with, the abductor pollicis longus.

The extensor pollicis brevis arises from the ulna distal to the abductor pollicis longus, from the interosseous membrane, and from the dorsal surface of the radius.

Its direction is similar to that of the abductor pollicis longus, its tendon passing the same groove on the lateral side of the lower end of the radius, to be inserted into the base of the first phalanx of the thumb.

Absence; fusion of tendon with that of the extensor pollicis longus.

In a close relationship to the abductor pollicis longus, the extensor pollicis brevis both extends and abducts the thumb at the carpometacarpal and metacarpophalangeal joints.

This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)