Palmar interossei muscles

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Palmar interossei muscles
The Interossei volares of left hand.
Latin	musculi interossei palmares
Gray's	subject #126 465
Origin:	metacarpals
Insertion:	proximal phalange
Artery:
Nerve:	deep branch of ulnar nerve
Action:	adduction
Antagonist:	Dorsal interossei of the hand
Dorlands/Elsevier	m_22/12549407

The palmar interossei (interossei volares) are small muscles in the hand that lie on the anterior aspect of the metacarpals. They are smaller than the dorsal interossei of the hand, which lie between the metacarpals.

Contents 1 Structure 2 Innervation 3 Actions 4 See also 5 External links

[edit] Structure

Each palmar interosseous muscle arises from the entire length of the metacarpal bone of one finger, and is inserted into the side of the base of the proximal phalanx and extensor expansion of the extensor digitorum tendon to the same finger.

There are three palmar interossei:

#	Origin	Insertion
first	from the ulnar side of the second metacarpal bone	into the same side of the proximal phalanx of the index finger
second	from the radial side of the fourth metacarpal bone	into the same side of the ring finger
third	from the radial side of the fifth metacarpal bone	into the same side of the little finger

The palmar interossei are unipennate.

From this account it may be seen that each finger is provided with two interossei, with the exception of the little finger, in which the abductor digiti minimi muscle takes the place of one of the pair.

Some texts consider the medial head of the flexor pollicis brevis to be a palmar interosseous muscle. This muscle would then be considered the first palmar interosseous muscle, and the total number of palmar interosseous muscles in the hand would be four.

[edit] Innervation

All of the interosseous muscles of the hand are innervated by the deep branch of the ulnar nerve.

[edit] Actions

The palmar interosseous muscles adduct the fingers towards the middle finger. This is in contrast to the dorsal interossei, which abduct the fingers away from the middle finger. The interossei also assist the lumbricals.

[edit] See also

• Plantar interossei muscles
• Dorsal interossei of the foot
• Dorsal interossei of the hand

[edit] External links

• UWASH interossei
• LUC pih
• GPnotebook -33161139
• Dictionary at eMedicine palmar+interosseous+muscle
• Mnemonic at medicalmnemonics.com 293 96
• PTCentral

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.

v • d • e Muscles of upper limbs

VERTEBRAL COLUMN: trapezius - latissimus dorsi - rhomboid major - rhomboid minor - levator scapulae ANTERIOR AND LATERAL THORACIC WALLS: pectoralis major - pectoralis minor - subclavius - serratus anterior SHOULDER: deltoid - rotator cuff (supraspinatus, infraspinatus, teres minor, subscapularis) - teres major ARM: anterior compartment: coracobrachialis - biceps brachii - brachialis posterior compartment: triceps brachii - anconeus FOREARM: anterior compartment super. - pronator teres - palmaris longus - flexor carpi radialis - flexor carpi ulnaris - flexor digitorum superficialis deep - pronator quadratus - flexor digitorum profundus - flexor pollicis longus posterior compartment super. - mobile wad (brachioradialis, extensor carpi radialis longus and brevis) - extensor digitorum, - extensor digiti minimi - extensor carpi ulnaris deep - supinator - anatomical snuff box (abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus) - extensor indicis HAND: Lateral volar - abductor pollicis brevis - thenar (opponens pollicis, flexor pollicis brevis, adductor pollicis) Medial volar - palmaris brevis - hypothenar (abductor minimi digiti, flexor digiti minimi brevis, opponens digiti minimi) Intermediate - lumbrical - dorsal interossei - palmar interossei