Abductor pollicis longus muscle Information & Abductor pollicis longus muscle Links at HealthHaven.com

Abductor pollicis longus muscle
	Front of right upper extremity. (Abductor pollicis longus labeled at upper left.)
	The mucous sheaths of the tendons on the back of the wrist. (Abductor pollicis longus and brevis visible at center right, going into thumb.)
Latin	musculus abductor pollicis longus
Gray's	subject #125 455
Origin	ulna, radial styloid process
Insertion	first metacarpal
Artery	Posterior interosseous artery
Nerve	Posterior interosseous nerve
Actions	abduction, extension of thumb
Antagonist	Adductor pollicis muscle

The Abductor pollicis longus lies immediately below the Supinator and is sometimes united with it.

[edit] Origin and insertion

It arises from the lateral part of the dorsal surface of the body of the ulna below the insertion of the Anconæus, from the interosseous membrane, and from the middle third of the dorsal surface of the body of the radius.

Passing obliquely downward and lateralward, it ends in a tendon, which runs through a groove on the lateral side of the lower end of the radius, accompanied by the tendon of the Extensor pollicis brevis, and is inserted into the radial side of the base of the first metacarpal bone.

It occasionally gives off two slips near its insertion: one to the greater multangular bone and the other to blend with the origin of the Abductor pollicis brevis.

[edit] Action

The chief action of abductor pollicis longus is to abduct the thumb at the carpo-metacarpal joint, thereby moving the thumb anteriorly.

By its continued action it helps to abduct the wrist.

[edit] Variations

More or less doubling of muscle and tendon with insertion of the extra tendon into the first metacarpal, the greater multangular, or into the Abductor pollicis brevis or Opponens pollicis.

[edit] See also

[edit] Additional images

Anatomical snuff box	Bones of left forearm. Posterior aspect.	Bones of the left hand. Volar surface.	Tendons of forefinger and vincula tendina.
Cross-section through the middle of the forearm.	Posterior surface of the forearm. Superficial muscles.	Posterior surface of the forearm. Deep muscles.	Transverse section across distal ends of radius and ulna.
Transverse section across the wrist and digits.	The muscles of the thumb.	The radial and ulnar arteries.	Deep palmar nerves.