Extensor pollicis brevis muscle
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| Extensor pollicis brevis muscle | ||
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| Front of right upper extremity. (Extensor pollicis brevis labeled at upper left.) | ||
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| Posterior surface of the forearm. Deep muscles. (Extensor pollicis brevis visible at left.) | ||
| Latin | musculus extensor pollicis brevis | |
| Gray's | subject #125 455 | |
| Origin: | radius | |
| Insertion: | thumb, proximal phalanx | |
| Artery: | posterior interosseous artery | |
| Nerve: | posterior interosseous nerve | |
| Action: | extension of thumb at metacarpophalangeal joint | |
| Antagonist: | Flexor pollicis longus muscle, Flexor pollicis brevis muscle | |
| Dorlands/Elsevier | m_22/12548946 | |
The Extensor pollicis brevis lies on the medial side of, and is closely connected with, the Abductor pollicis longus.
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[edit] Origin and insertion
It arises from the dorsal surface of the body of the radius below that muscle, and from the interosseous membrane.
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.
[edit] Action
The Extensor pollicis brevis extends the proximal phalanx.
[edit] Variations
Absence; fusion of tendon with that of the Extensor pollicis longus.
[edit] Additional images
 Bones of left forearm. Posterior aspect. |
 Bones of the left hand. Dorsal surface. |
 Tendons of forefinger and vincula tendina. |
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 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. |
[edit] External links
This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.
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