What is the main function of the diaphragm?

The diaphragm is the principal muscle of inspiration. When it contracts, it flattens to increase thoracic volume, allowing air to enter the lungs. It also aids in abdominal straining, weight lifting, venous return, and acts as an esophageal sphincter.

Where does the diaphragm originate from?

The diaphragm originates from three main parts: Sternal part from the xiphoid process, costal part from the lower six ribs and costal cartilages, and vertebral part via crura and arcuate ligaments attached to lumbar vertebrae.

What are the major openings in the diaphragm and what do they transmit?

The diaphragm has three major openings: Vena caval opening (T8) transmits the inferior vena cava and right phrenic nerve; esophageal opening (T10) transmits the esophagus, vagal trunks, and left gastric artery branches; aortic opening (T12) transmits the aorta, thoracic duct, and azygos vein.

How is the diaphragm innervated?

The diaphragm is innervated by motor supply from the phrenic nerves (C3–C5) and sensory supply from phrenic nerves centrally and intercostal/subcostal nerves peripherally.

What are some common clinical conditions related to the diaphragm?

Common conditions include diaphragmatic paralysis from phrenic nerve injury, hiccups from involuntary spasms, and diaphragmatic hernias like Bochdalek, Morgagni, or hiatal hernias.

What structures are related to the inferior surface of the diaphragm?

The inferior surface relates to abdominal organs: on the right side, liver, right kidney, and right suprarenal gland; on the left side, liver, stomach, spleen, left kidney, and left suprarenal gland.

What is the central tendon of the diaphragm?

The central tendon is the fibrous central portion where all muscle fibers insert. It is trifoliate in shape, fused with the fibrous pericardium, and located closer to the sternum than the vertebral column.

Diaphragm – Anatomy, Openings & Respiration

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