- Pectoralis minor muscle
Muscle infobox
Name = Pectoralis minor
Latin = musculus pectoralis minor
GraySubject = 122
GrayPage = 438
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Origin = 3rd to 5thrib s, near theircostal cartilages
Insertion = medial border and superior surface of thecoracoid process of thescapula
Blood =Pectoral branch of thethoracoacromial trunk
Nerve =Medial pectoral nerve (C8, T1)Lateral pectoral nerve
Action = It stabilizes thescapula by drawing it inferiorly and anteriorly against thethoracic wall .
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DorlandsPre = m_22
DorlandsSuf = 12550138
The Pectoralis minor is a thin, triangular muscle, situated at the upper part of thechest , beneath thePectoralis major .Origin and insertion
It arises from the upper margins and outer surfaces of the third, fourth, and fifth
rib s, near their cartilages 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 thescapula .Relations
The pectoralis minor muscle is covered anteriorly (superficially) by the
clavipectoral fascia . Themedial 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.
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* [http://faculty.ucc.edu/biology-potter/Musculature/sld014.htm Slide]
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