ribs

There are 206 bones in the adult body, nearly half of them in the hands and feet. The adult human body also has approximately 100 joints.

Arched bones that form the wall of the thorax (chest). There are 24 ribs in humans. Together with the sternum and backbone, they form a bony framework that protects the internal organs.

The upper seven ribs on each side are called the true or vertebro-sternal ribs, as they articulate with the thoracic vertebrae in the back and are joined to the sternum (breast-bone) by cartilages at the front; the next four on each side are called the false or vertebro-costal ribs, as their front extremities are joined to each other, not to the sternum; the lowest is known as the floating or vertebral rib, as its front extremity is free.

The diaphragm and muscles between adjacent ribs are responsible for the respiratory movements which fill the lungs.