Extensor pollicis longus muscle
|Extensor pollicis longus muscle|
|The mucous sheaths of the tendons on the back of the wrist. (Extensor pollicis longus visible at center right.)|
|Latin||musculus extensor pollicis longus|
|Gray's||subject #125 455|
|Insertion:||thumb, distal phalanx|
|Nerve:||posterior interosseus nerve (branching from the radial nerve)|
|Action:||extension of the thumb (metacarpophalangeal and interphalangeal)|
|Antagonist:||Flexor pollicis longus muscle, Flexor pollicis brevis muscle|
The Extensor pollicis longus is much larger than the Extensor pollicis brevis muscle, the origin of which it partly covers.
Origin and insertion
It ends in a tendon, which passes through a separate compartment in the dorsal carpal ligament, lying in a narrow, oblique groove on the back of the lower end of the radius.
It then crosses obliquely the tendons of the Extensores carpi radialis longus and brevis, and is separated from the Extensor brevis pollicis by a triangular interval, the anatomical snuff box in which the radial artery is found; and is finally inserted into the base of the last phalanx of the thumb.
The extends the proximal phalanx, and the
Posterior surface of the forearm. Deep muscles.
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 As such, some of the information contained herein may be outdated.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.