Xiphoideus

The xiphoideus, in anatomy often referred to as the xiphoid process (processus xiphoideus in Latin), is the small, most inferior part of the sternum. It normally begins as a cartilaginous projection at the lower end of the sternum and tends to ossify with age, often fusing with the body of the sternum in adulthood.

Anatomically, the xiphoid process lies at the inferior tip of the sternum and serves as an attachment site for several structures. The diaphragm originates from the posterior and inferior surfaces near the xiphoid, while the abdominal muscles, including the rectus abdominis, attach to the region around the xiphoid. The xiphisternal joint marks the junction between the xiphoid process and the body of the sternum.

Clinical significance and variation are notable. The xiphoid process is a useful anatomical landmark in procedures such as cardiopulmonary resuscitation, where hand placement is guided to avoid injury to the process. It can be subjected to trauma, fracture, or inflammation; in some individuals the xiphoid is elongated, bifid, or calcified with age, which may cause discomfort or pain known as xiphoidalgia.

In summary, the xiphoid process is a small, variable, cartilaginous structure at the sternum’s inferior end that ossifies with age and serves as an attachment point for the diaphragm and abdominal muscles, while also functioning as a key clinical landmark.