Pectoralis major (left) (Musculus pectoralis major)
Educational content only — not medical advice.
Anatomy
A powerful fan-shaped muscle covering the chest in three parts (clavicular, sternocostal, abdominal) that converge into one tendon — the prime mover that hugs the arm against the body.
Origin & insertion
Origin: medial half of the clavicle, sternal surface, costal cartilages 1–6 and the abdominal aponeurosis. Insertion: lateral lip of the humeral intertubercular groove.
Action
Adducts and medially rotates the arm; extends the flexed shoulder.
Innervation
Lateral and medial pectoral nerves (C5–T1)
Clinical notes
Its tendon tears in heavy lifting with a palpable pop and lump on resisted flexion; the anterior axillary fold loses its contour after surgical lymph-node removal.
Related structures
Educational references
FAQ
What is the role of the Pectoralis major (left)?
A powerful fan-shaped muscle covering the chest in three parts (clavicular, sternocostal, abdominal) that converge into one tendon — the prime mover that hugs the arm against the body.
Why is the Pectoralis major (left) clinically important?
Its tendon tears in heavy lifting with a palpable pop and lump on resisted flexion; the anterior axillary fold loses its contour after surgical lymph-node removal.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details