Pectoralis major muscle facts for kids

Muscles on top of the chest and front of the arm

The pectoralis major is a thick, fan-shaped muscle, on the chest (front) of the human body.

It makes up most of the the chest muscles, and is under the breast. In sports as well as bodybuilding, the pectoral muscles may be referred to as "pecs", "pectoral muscle" or "chest muscle" because it is the larger surface muscle in the chest area.

Images for kids

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  Absence of sternocostal head of right pectoralis major associated with compensatory hypertrophy of latissimus dorsi is not rare. It is revealed on pressing downwards with the arms.

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  The function of the pectoralis major is different for its different heads. The clavicular head flexes the humerus, and the sternocostal head adducts the humerus. As a whole the action is to adduct and medially rotate the humerus. It also draws the scapula anteriorly and inferiorly.

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  Activation and protection of the Pectoralis major by a gymnast using talc.

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  Pectoralis major highlighted on the trunk – frontal view

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  Anterior surface of sternum and costal cartilages, showing origins

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  Left clavicle. Superior surface, showing origins.

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  Left clavicle. Inferior surface, showing origins.

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  Left humerus. Anterior view, showing insertion.

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  The axillary artery and its branches

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  The brachial artery

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  The right brachial plexus with its short branches, viewed from in front

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  The right brachial plexus (infraclavicular portion) in the axillary fossa; viewed from below and in front

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  Nerves of the left upper extremity

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  The left side of the thorax

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  Pectoralis major muscle

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  An individual with an abdominal portion of the pectoralis major, and an accessory sternalis muscle. Both these are anatomical variations.

See also

In Spanish: Músculo pectoral mayor para niños