Sternum
Sternum Terminology
‘Sternum’ is derived from the Greek word ‘sternum’ which means chest. Sternum is also called ‘breast bone’.
It has three parts; manubrium, body, and xiphoid process. The manubrium is a Latin word that means ‘handle’. The term ‘xiphoid’ is borrowed from the Greek word ‘xiphos’ which means ‘sword’.
Sternum Location
It is a flat bone whose long axis is vertical. It lies in the median part of the anterior thoracic wall. Its surfaces are anterior and posterior. Its anterior surface also faces a little upwards.
Sternum Length
It is about 7 inches (17 cm) long.
Sternum Structure
It is made up of mainly spongy bone and thus it is rich in red bone marrow.
Sternum Features
Sternum is made up of three pieces from above downwards:
- Manubrium.
- Body.
- Xiphoid process.
Sternum Manubrium
It is somewhat triangular in shape and is wider above than below. It has two surfaces (anterior and posterior) and four borders (superior, inferior, and two lateral).
Sternum The Body
It has two surfaces (anterior and posterior), two borders (right lateral
Sternum Xiphoid Process
It is the lowest and smallest part of the sternum and is of variable shape. It has two surfaces (anterior and posterior), two borders (right lateral and left lateral), and two ends (upper and lower).