The human rib cage is made up of 12 paired rib bones each are symmetrically paired on a right and left side. Although fixed into place, these ribs do allow for some outward movement, and this helps stabilize the chest during inhalation and exhalation.

At the chest, many rib bones connect to the sternum via costal cartilage, segments of hyaline cartilage that allow the rib cage to expand during respiration. The rib cage is collectively made up of long, curved individual bones with joint-connections to the spinal vertebrae. To examine joints and learn about muscles and the movements they produce, the names of the bones of the body and the anatomic landmarks of each bone must be looked at in greater detail (see Table 3.1).The ribs partially enclose and protect the chest cavity, where many vital organs (including the heart and the lungs) are located. Sesamoid bones help reduce friction and stress on tendons and may also help to change the direction of tension placed on the tendon. Other sesamoid bones are often found around the knee joint or the joints of the hands or feet. These bones are called sesamoid bones. The patella is a sesamoid bone found in all individuals. Rarely, small, flat, round bones develop inside ten-dons. The number, size, and shape vary by individual. Small, irregularly shaped bones, called sutural or wormian bones, are found where two ormore other bones meet in the skull. The facial bones and vertebrae are all examples of this type. Irregular bones are those in various shapes andsizes. Flat bones contain the red bone marrow in which blood cells are manufactured. Their thin, broad area helps protect inner organs and/or provide surface area for muscle attachment. The shoulder blade (scapula), some of the skull bones, ribs, and breastbone (ster-num), are all examples of flat bone. Most of the carpals-the small bones lo-cated in the wrist (except pisiform, sesamoid bone)- and most of the tarsals-the small bones in the ankle region (except calcaneus, irregular bone)-are good examples of short bones.įlat bones are broad and thin with a flattenedand/or curved surface. Short bones are almost equal in length, width,and height.

The femur or thighbone, the humerus of the arm, metacarpals, metatarsals, and phalanges are a few examples. Long bones, as thename suggests, are long, with the length being greater than the width. The bones of the body are classified, according to shape, as long bones, short bones, flat bones, and irregular bones (see Figure 3.4).

Are ribs a flat bone