There is a bone in the middle of the chest cavity that connects the middle of the two clavicles on top, and directly to the junction diaphragm of the thoracic and abdominal cavities at the bottom; this bone is called the sternal stalk, and below it is called the body of the sternum, and at the very end a pointed projection is called the xiphoid process. They connect the ten pairs of ribs in the chest, which connects 20 bones, with many nerves, lymphatics and important blood vessels running through the center. The middle bone is used to connect the ribs, thus serving to protect the organs in the chest cavity, and is one of the very important bones in the human body.