Anatomy of the Shoulder

The shoulder is made up of several layers, including:

• Bones. The collarbone (clavicle), the shoulder blade (scapula), and the upper arm bone (humerus).
• Joints. The place where movement occurs, including the following:
• Ligaments. White, shiny, flexible bands of fibrous tissue that hold joints together and connect various bones, including:
• Acromion. The roof or highest point of the shoulder that is formed by a part of the scapula.
• Tendons. The tough cords of tissue that connect muscles to bones. The rotator cuff tendons are a group of tendons that connect the deepest layer of muscles to the humerus.
• Muscles. Help support and rotate the shoulder in many directions. Facilitate movement of the shoulder. 
• Rotator cuff. Name of a group of muscles and tendons that rotate and raise the shoulder.
• Bursa. A closed space between 2 moving surfaces that has a small amount of lubricating fluid inside. It is located between the rotator cuff muscle layer and the outer layer of large, bulky muscles.