|Origin||The anterior surface and the medial half of clavicle
The anterior surface of sternum
The superior six costal cartilages
Aponeurosis of the external oblique muscle
|Insertion||The lateral lip of the bicipital groove|
Humeral medial rotation
Humeral flexion (clavicular head)
Humeral extension (sternocostal head)
|Nerve||Medial and lateral pectoral nerves (C5-T1)|
|Artery||Pectoral branch of the thoracoacromial trunk|
Location & Overview
The pectoralis major is a muscle which makes up the bulk of the chest. It is sometimes referred to as the ‘pecs’. It is a fan shaped muscle which lies atop of the pectoralis minor and serratus anterior muscles. The pectoralis major is commonly divided into two heads when describing it. The clavicular head (which is comprised of the superior portion closest to the clavicle) and the sternocostal head (which is the inferior portion originating from the sternum)   .
Origin & Insertion
The pectoralis major originates from the anterior surface of the medial half of the clavicle, the anterior surface of the sternum, the superior six costal cartilages and the aponeurosis of the external oblique muscle. It then inserts at the lateral lip of humerus’s bicipital groove (also known as the intertubercular groove)   .
The pectoralis major’s actions are: humeral adduction, medial rotation of the humerus, the clavicular head can cause flexion of the humerus and the sternocostal head can cause extension of the humerus  .
The pectoralis major is innervated by the medial and lateral pectoral nerves (C5-T1) .
Blood is supplied from the pectoral branch of the thoracoacromial trunk .
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Pectoralis Major Flashcards
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|↑2||Sanchez ER, Sanchez R, Moliver C. Anatomic relationship of the pectoralis major and minor muscles: a cadaveric study. Aesthet Surg J. 2014 Feb;34(2):258-63. doi: 10.1177/1090820X13519643. Epub 2014 Jan 8. PMID: 24402060.|
|↑3, ↑6||Moore KL, Agur AMR, Dalley AF. Clinically Oriented Anatomy. 8th ed. Philadelphia: Lippincot Williams & Wilkins; 2017.|
|↑4, ↑7, ↑9, ↑10||Solari F, Burns B. Anatomy, Thorax, Pectoralis Major Major. [Updated 2021 Jul 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK525991/|
|↑5, ↑8||Baig MA, Bordoni B. Anatomy, Shoulder and Upper Limb, Pectoral Muscles. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK545241/|