diafragman

Diafragma, or diafragman in several languages, is a dome-shaped musculotendinous partition that separates the thoracic and abdominal cavities. It is the principal muscle of inspiration and plays a key role in breathing, coughing, and other actions that alter thoracoabdominal pressures.

Anatomy: The diaphragm attaches anteriorly to the xiphoid process, laterally to the inner surfaces of the lower six ribs and their costal cartilages, and posteriorly to the upper lumbar vertebrae via the left and right crura. Its central part forms a strong aponeurotic tendon, the central tendon, which is anchored to the pericardium. The right dome sits higher than the left due to the liver.

Neurovascular supply: The diaphragm is innervated mainly by the phrenic nerves (C3–C5), which provide motor control and sensation to the central portion. Peripheral diaphragmatic areas receive sensory input from intercostal nerves. Blood supply comes primarily from the inferior phrenic arteries, with contributions from the superior phrenic and musculophrenic arteries; venous drainage is via the phrenic veins to the inferior vena cava and, on the left, to the azygos system.

Physiology: When the diaphragm contracts, its fibers pull the central tendon downward and flatten the dome, increasing thoracic volume and reducing intrathoracic pressure to draw air into the lungs. Relaxation allows passive expiration. The diaphragm also raises intra-abdominal pressure during activities such as vomiting, defecation, and parturition and aids venous return to the heart during inspiration.

Clinical relevance: Congenital diaphragmatic hernias (Bochdalek and Morgagni), diaphragmatic eventration, and diaphragmatic paralysis from phrenic nerve injury are notable conditions. Hiatal hernia, where part of the stomach protrudes through the esophageal hiatus, is also related to diaphragmatic function. Imaging and surgical management address these conditions as needed.