diaphragmatic

Diaphragmatic is an anatomical term meaning relating to the diaphragm, the primary muscle responsible for breathing. The diaphragm is a dome-shaped musculotendinous sheet that forms the boundary between the thoracic and abdominal cavities. It works in concert with the intercostal muscles to enable respiration, and its proper function is essential for effective ventilation.

Anatomy and structure: The diaphragm has a central tendinous part (the central tendon) and muscular portions that originate from the sternum, lower ribs, and lumbar spine. The three major muscular parts are the sternal, costal, and lumbar components, with the crura anchoring the diaphragm to the lumbar vertebrae. The phrenic nerves (originating from C3 to C5) provide motor innervation, enabling contraction, while small sensory fibers carry sensation from the diaphragmatic pleura and peritoneum. Blood supply comes from the inferior phrenic arteries and the superior phrenic arteries. The diaphragm also forms several openings (hiatuses) for the esophagus, aorta, and inferior vena cava.

Function: During inspiration, diaphragmatic contraction lowers the dome, enlarging the thoracic cavity and drawing air into the lungs. Relaxation allows passive expiration. The diaphragm also increases intra-abdominal pressure during activities such as vomiting, defecation, and parturition, and it facilitates venous return by promoting negative intrathoracic pressure. Diaphragmatic movement can be consciously controlled to some degree, a principle used in diaphragmatic breathing techniques.

Clinical relevance: Diaphragmatic disorders include congenital diaphragmatic hernia, diaphragmatic eventration, and diaphragmatic paralysis from phrenic nerve injury. Conditions affecting the diaphragm can impair ventilation and may require imaging, respiratory therapy, or surgical intervention.

See also: diaphragmatic breathing, diaphragmatic hernia, phrenic nerve.