Diaphragm (anatomy)
Anatomy and Structure
The diaphragm is a dome-shaped, muscular and fibrous structure that separates the thoracic cavity from the abdominal cavity. It is the primary muscle involved in the process of breathing, playing a crucial role in inhalation and exhalation.
The diaphragm is composed of two parts: the peripheral muscle and the central tendon. The peripheral muscle originates from the lumbar vertebrae, the lower six ribs, and the xiphoid process of the sternum. The central tendon, which is the strongest part of the diaphragm, is a thin but strong aponeurosis situated at the center of the diaphragm.
Function
The primary function of the diaphragm is to facilitate breathing. During inhalation, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity and decreasing the pressure, allowing air to flow into the lungs. During exhalation, the diaphragm relaxes and moves upward, decreasing the volume of the thoracic cavity and increasing the pressure, forcing air out of the lungs.
The diaphragm also plays a role in non-respiratory functions. It assists in the expulsion of vomit, feces, and urine by increasing intra-abdominal pressure, and aids in the prevention of acid reflux by exerting pressure on the esophagus as it passes through the esophageal hiatus.
Clinical Significance
Conditions affecting the diaphragm can lead to breathing difficulties and other health problems. Diaphragmatic hernias, for example, occur when abdominal organs push through a weakness in the diaphragm, potentially leading to life-threatening complications. Diaphragmatic paralysis, in which the diaphragm cannot contract, can result in respiratory failure.