Flexor digitorum profundus muscle

Flexor digitorum profundus muscle
Ventral view of the deep muscles of the forearm. FDP is shown in blue.
Latin	musculus flexor digitorum profundus
Gray's	subject #125 448
Origin	ulna
Insertion	distal phalanges
Artery	anterior interosseous artery
Nerve	median (anterior interosseous), muscular branches of ulnar
Actions	flex hand, interphalangeal joints
Antagonist	Extensor digitorum muscle

In human anatomy, the flexor digitorum profundus is a muscle in the forearm that flexes the fingers. It is considered to be an extrinsic muscle because its action is at a different location than the main body of the muscle.

Flexor digitorum profundus, along with flexor digitorum superficialis have long tendons that run down the arm and through the carpal tunnel and attach to the palmar side of the phalanges of the fingers. This muscle originates from the upper 3/4ths anterior and medial side of the ulna.

Flexor digitorum profundus lies deep to superficialis, but it attaches more distally. To get around this problem profundus's tendons go through the tendons of superficialis, and end up attaching to the distal phalanx.

Innervation

Flexor digitorum profundus is innervated by the median and ulnar nerves.

• The medial aspect of the muscle (which flexes the 4th and 5th digit) is supplied by the ulnar nerve (C8, T1)
• The lateral aspect (which flexes the 2nd and 3rd digit) by the median nerve (via its anterior interosseous branch) (C8, T1).

It is one of two flexor muscles that is not exclusively supplied by the median nerve (the other is flexor carpi ulnaris).

Origin

Flexor Digitorum Profundus originates upper 3/4 of anterior & medial surfaces of ulna, interosseous membrane and deep fascia of the forearm.

Insertion

The Muscle fans out into four tendons (one to each of the 4 palmar finger) to the palmer base of distal phalanx.

Additional images

Bones of left forearm. Anterior aspect.	Bones of left forearm. Posterior aspect.	Bones of the left hand. Volar surface.	Front of the left forearm. Deep muscles.
Cross-section through the middle of the forearm.	Posterior surface of the forearm. Deep muscles.	Transverse section across distal ends of radius and ulna.	Transverse section across the wrist and digits.
The mucous sheaths of the tendons on the front of the wrist and digits.	Ulnar and radial arteries. Deep view.	Tendons of forefinger and vincula tendina. (Flexor digitorum profundus labeled at bottom right.)

External links

• LUC fdp
• UWASH flexordigprofundus