A
diaphragm is some sort of separating membrane. This gives rise to several meanings:
In
anatomy, the
diaphragm is a shelf of
muscle extending across the bottom of the
ribcage, providing the floor to the
thoracic cavity and the ceiling to the
abdominal cavity. It is critically important in
respiration, helping to expel air from the
lungs when elevated and to draw air into the lungs when depressed. A hiatal hernia is a tear in the diaphragm.
A diaphragm is a sheet of a semi-flexible material, anchored at its periphery, and most often round in shape. It serves either as a barrier between two chambers, moving slightly up into one chamber or down into the other depending on differences in
pressure, or as a device that vibrates when certain frequencies are somehow applied to it. In this last sense, the human
eardrum is a diaphragm. Pressure-flush valves in
urinals[?] work by means of an internal diaphragm.
A diaphragm is also a method of contraception.