The musculotendinous diaphragm seals the inferior thoracic aperture.
Generally, muscle fibers of the diaphragm arise radially, from the margins of the inferior thoracic aperture, and converge into a large central tendon.
Because of the oblique angle of the inferior thoracic aperture, the posterior attachment of the diaphragm is inferior to the anterior attachment.
The diaphragm is not flat; rather, it "balloons" superiorly, on both the right and left sides, to form domes. The right dome is higher than the left, reaching as far as rib V.