Parts of the shoulder

These are the different parts of the shoulder as viewed from the front (A) and the back (B). The shoulder joint is made up of the upper arm bone, collarbone, and shoulder blade. Ligaments, muscles, and tendons help hold the joint in place and allow you to move your arm. A "bursa" is a small fluid-filled sac that sits near a bone. It cushions and protects nearby tissues when they rub on or slide over bones.