Diaphragm
From the Simple English Wikipedia, the free encyclopedia that anyone can change
The diaphragm is a muscle that is at the bottom of the ribcage of mammals.
[change] What it does
When breathing in, the diaphragm pulls down so that the size of the lungs increases. When breathing out, the diaphragm rests and goes up making a dome shape, decreasing the size of the lungs and pushing air out.
[change] See also