Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
The pectoralis major is a large muscle in the upper chest, fanning across the chest from the shoulder to the sternum. It is responsible for movements such as flexing, rotating, and adducting the arm.
Related terms
Deltoid: A triangular muscle on the shoulder that is involved in arm rotation and stabilization.
Latissimus dorsi: A broad muscle on the back that supports arm movement and contributes to the motion of pulling things towards oneself.
Sternal: Pertaining to the sternum (breastbone), often used in reference to parts of muscles attached to the sternum, like parts of the pectoralis major