Extensor pollicis brevis muscle

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
Latin	musculus extensor pollicis brevis
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
Gray's	p.455
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.

Structure

The extensor pollicis brevis arises from the radius distal to the abductor pollicis longus, from the interosseous membrane, and from the dorsal surface of the radius. ^[1]

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.

Variation

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

Function

In a close relationship to the abductor pollicis longus, the extensor pollicis brevis both extends and abducts the thumb^[1] at the carpometacarpal and metacarpophalangeal joints.^[2]

Additional images

Anatomical snuff box  Bones of left forearm. Posterior aspect.  Bones of the left hand. Dorsal surface.  Tendons of forefinger and vincula tendina.  Transverse section across distal ends of radius and ulna.  Transverse section across the wrist and digits.  The mucous sheaths of the tendons on the back of the wrist.  The radial and ulnar arteries.  Arteries of the back of the forearm and hand.  Extensor carpi radialis brevis muscle  Extensor pollicis brevis muscle  Extensor pollicis brevis muscle  Extensor pollicis brevis muscle  Extensor pollicis brevis muscle  Extensor pollicis brevis muscle  Extensor pollicis brevis muscle  Extensor pollicis brevis muscle  Muscle of the hand.Posterior view.

References

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

Sources

• Platzer, Werner (2004). Color Atlas of Human Anatomy, Vol. 1: Locomotor System (5th ed.). Thieme. ISBN 3-13-533305-1. 

External links

Wikimedia Commons has media related to Extensor pollicis brevis muscle.

• 40566785 at GPnotebook
• Extensor+pollicis+brevis+muscle at eMedicine Dictionary
• PTCentral