Xiphoid process

The xiphoid process, or xiphisternum or metasternum, is a small cartilaginous

Cartilage

Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...

 process

Process (anatomy)

In anatomy, a process is a projection or outgrowth of tissue from a larger body. The vertebra has several kinds of processes,such as: transverse process, prezygapophysis, postzygapophysis.-Examples:Examples of processes include:...

 (extension) of the lower part of the sternum which is usually ossified

Ossification

Ossification is the process of laying down new bone material by cells called osteoblasts. It is synonymous with bone tissue formation...

 in the adult human. By age 15 to 29, the xiphoid usually fuses to the body of the sternum with a fibrous joint. Unlike the synovial articulation of major joints, this is non-movable. Much the way the first seven ribs articulate with the sternum, the cartilage in the celiac plexus

Celiac plexus

The celiac plexus or coeliac plexus, also known as the solar plexus, is a complex network of nerves located in the abdomen, where the celiac trunk, superior mesenteric artery, and renal arteries branch from the abdominal aorta...

 joins on the xiphoid process, reinforcing it, and indirectly attaches the costal cartilage to the sternum. In newborn babies and young (especially slender) infants, the tip of the xiphoid process may be both seen and felt as a lump just below the sternal notch.

Bifurcation

The xiphoid process can be naturally bifurcated, and sometimes perforated. These variances in morphology are inheritable, which can help group family members together when dealing with burial remains. These morphological differences pose no health risk, and are simply a difference in form.

Clinical significances

Pressure on the xiphoid process should be avoided when administering chest compressions in CPR

Cardiopulmonary resuscitation

Cardiopulmonary resuscitation is an emergency procedure which is performed in an effort to manually preserve intact brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person in cardiac arrest. It is indicated in those who are unresponsive...

, as this can cause the xiphoid process to break off, resulting in punctures or lacerations of the diaphragm

Thoracic diaphragm

In the anatomy of mammals, the thoracic diaphragm, or simply the diaphragm , is a sheet of internal skeletal muscle that extends across the bottom of the rib cage. The diaphragm separates the thoracic cavity from the abdominal cavity and performs an important function in respiration...

. The xiphoid process is considered to be at the level of the 9th thoracic vertebrae and the T6 dermatome.

Xiphoid process in birds

In birds, the xiphoid process is a long structure, often following the direction of the carinatae

Carinatae

This article is about bird taxonomy; for the topic in pottery and glassware design, see Carinate.The Carinatae are, in phylogenetic taxonomy, the last common ancestor of the Neornithes and Ichthyornis , and all its descendants...

.

Etymology

The word derives from the Greek

Greek language

Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...

 word xiphos for straight sword, the tip of which the process somewhat resembles.