Pectoral Muscles
The pectoral is a term relating to the chest. The "pectoralis major" is
a large, fan-shaped muscle that covers much of the front upper chest. It
begins at the breastbone (sternum) and the cartilage of the second to the
sixth ribs and is attached to the collarbone (clavicle) to converge on the
upper arm bone (humerus) just below the shoulder. Its main use is in
moving the arm across the body. The "pectoralis minor" is a smaller,
triangular muscle beneath the pectoralis major. It stems from the third
to fifth ribs and converges at the shoulder blade (scapula), which it
moves up and down.