Thoracic diaphragm

Diaphragm
Respiratory system
Details
Origin	Septum transversum, pleuroperitoneal folds, body wall[1]
Artery	Pericardiacophrenic artery, musculophrenic artery, inferior phrenic arteries
Vein	Superior phrenic vein, inferior phrenic vein
Nerve	Phrenic and lower intercostal nerves
Identifiers
Latin	diaphragma
Greek	διάφραγμα
MeSH	D003964
TA98	A04.4.02.001
TA2	2327
FMA	13295
Anatomical terms of muscle [edit on Wikidata]

The thoracic diaphragm, or simply the diaphragm (/ˈdaɪəfræm/;^[2] Ancient Greek: διάφραγμα, romanized: diáphragma, lit. 'partition'), is a sheet of internal skeletal muscle^[3] in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the most important muscle of respiration,^[4] and separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity: as the diaphragm contracts, the volume of the thoracic cavity increases, creating a negative pressure there, which draws air into the lungs.^[5] Its high oxygen consumption is noted by the many mitochondria and capillaries present; more than in any other skeletal muscle.^[4]

The term diaphragm in anatomy, created by Gerard of Cremona,^[6] can refer to other flat structures such as the urogenital diaphragm or pelvic diaphragm, but "the diaphragm" generally refers to the thoracic diaphragm. In humans, the diaphragm is slightly asymmetric—its right half is higher up (superior) to the left half, since the large liver rests beneath the right half of the diaphragm. There is also speculation that the diaphragm is lower on the other side due to heart's presence.

Other mammals have diaphragms, and other vertebrates such as amphibians and reptiles have diaphragm-like structures, but important details of the anatomy may vary, such as the position of the lungs in the thoracic cavity.