Pectoralis minor muscle
The Pectoralis minor is a thin, triangular muscle, situated at the upper part of the chest, beneath the Pectoralis major.
Origin and insertion
It arises from the upper margins and outer surfaces of the third, fourth, and fifth ribs, near their cartilage and from the aponeuroses covering the Intercostalis.
The fibers pass upward and lateralward and converge to form a flat tendon, which is inserted into the medial border and upper surface of the coracoid process of the scapula.
Relations
The pectoralis minor muscle is covered anteriorly (superficially) by the clavipectoral fascia. The medial pectoral nerve pierces the pectoralis minor and the clavipectoral fascia.
Actions
The Pectoralis minor depresses the point of the shoulder, drawing the scapula downward and medialward toward the thorax, and throwing the inferior angle backward.
Variations
Origin from second, third and fourth or fifth ribs. The tendon of insertion may extend over the coracoid process to the greater tubercle. May be split into several parts. Absence rare.
Additional images
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 As such, some of the information contained herein may be outdated.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.
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List of muscles of upper limbs |
| VERTEBRAL COLUMN |
trapezius - latissimus dorsi - rhomboid (major, minor) - levator scapulae |
| 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 - thenar (opponens pollicis, flexor pollicis brevis, abductor 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 |
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