Extensor pollicis longus muscle

Template:Muscle infobox In human anatomy , the extensor pollicis longus is a skeletal muscle located dorsally on the forearm. It is much larger than the extensor pollicis brevis, the origin of which it partly covers, and acts to stretch the thumb together with this muscle.

Origin and insertion

It arises from the dorsal surface of the ulna and from the interosseous membrane.

Passing through the third tendon compartment, lying in a narrow, oblique groove on the back of the lower end of the radius, its tendon is inserted on the base of the distal phalanx of the thumb. It uses the dorsal tubercle on the radius as fulcrum.

It crosses obliquely the tendons of the extensores carpi radialis longus and brevis, and is separated from the extensor pollicis brevis by a triangular interval, the anatomical snuff box in which the radial artery is found.

Relations

Together with the tendons of the extensor pollicis brevis and the abductor pollicis longus, its tendon crosses the radial artery.

Action

Extensor pollicis longus extends the terminal phalanx of the thumb; in combination with the extensor pollicis brevis, it helps to extend and abduct the wrist.

References

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

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained within it may be outdated.

External links

• Template:MuscleLoyola
• 33947649 at GPnotebook
• Extensor+pollicis+longus+muscle at eMedicine Dictionary
• PTCentral

Template:Muscle-stubgl:Músculo extensor longo do polgar