A thick and fan-shaped like muscle, the pectoralis major is essentially the main component of a male chest and lies beneath the breast tissue in women. Below this muscle lies the pecoralis minor. Responsible for the movement of the shoulder joint primarily, the pectoralis major has four major actions.
There is a large array of exercises available to focus on the pectoralis muscle including the four major regions of upper, lower, middle and outer. The most common are pressing exercises, flyes and dips. Some are more focused than others and provide different results such as thickening and strengthening the chest muscles or others such as shaping or adding striations.