The structure between the breast and the clavicle in the chest has ribs, rib cartilage, intercostal muscles and other chest muscles. The ribs are the human trunk bone structure, mainly responsible for forming the contours of the chest and can play a protective role for the important internal organs of the chest cavity. The rib cage is a long semi-elliptical bone structure, connected to the spine and the sternum on the left and right sides respectively, and is relatively hard. When exhaling, the thoracic elasticity and the pulling force of the intercostal muscles are used to expel the gas out of the body. The other muscles of the chest mainly control the movement of the arms.