The sternum is a bone that lies in the anterior midline of our thorax.
It forms part of the rib cage and the anterior-most part of the thorax. The sternum protects the thoracic organs from mechanical injury, provides attachment sites for various muscles, and also is the centre around which the superior ten ribs are directly or indirectly attached.
The sternum consists of three parts:
- Manubrium of the sternum - the most superior part that articulates with clavicles and the first pair of ribs
- Body of the sternum - the middle part that articulates with 3rd to 7th ribs
- Xiphoid process - the most inferior part, which is usually pointed
At the centre of the superior border of the manubrium, the jugular notch (also known as the suprasternal or presternal notch) is present. There are also indentations called the clavicular notches for articulation with the clavicles on each side of the upper part of the sternum. The lower border of the manubrium articulates with the body of the sternum at the sternal angle.