diaphragmen

Diaphragmen is a term used in some contexts to refer to the diaphragm, the musculotendinous partition between the thoracic and abdominal cavities. The diaphragm comprises a peripheral muscular portion and a central tendinous part. It originates from the xiphoid process, the lower ribs, and the lumbar vertebrae, and it inserts into the central tendon. The major openings include the caval opening for the inferior vena cava (at T8), the esophageal hiatus for the esophagus (T10), and the aortic hiatus for the aorta (T12). The left and right crura anchor the posterior part of the muscle.

The diaphragm is primarily innervated by the phrenic nerve (C3–C5), which provides motor control. Sensory innervation arises from the central portion via the phrenic nerves, while the peripheral portions receive sensory input from lower intercostal nerves.

As the principal muscle of inspiration, the diaphragm contracts and moves downward, increasing the volume of the thoracic cavity and lowering intrathoracic pressure to draw air into the lungs. It relaxes during expiration. The muscle also contributes to abdominal pressure during coughing, vomiting, and lifting. Clinically relevant conditions include diaphragmatic paralysis from phrenic nerve injury, diaphragmatic eventration, and diaphragmatic hernias. Congenital defects may present in infancy, while acquired defects can follow trauma or surgical procedures.

Etymology and usage: the spelling “diaphragmen” appears in some older texts or as a transliteration variant; the standard modern English spelling is “diaphragm.” The term derives from Latin diaphragma and Greek diaphragma (diaphragma).