Thanks to everyone that joined us for Yoga class this week. Here is an answer to Louise's excellent question.
The diaphragm is the primary muscle of respiration. It flattens out to expand the ribs and make room for the lungs during inhalation. It domes up to form around the heart and lungs during exhalation. Filling our belly as we inhale draws the diaphragm down increasing the space for the lungs to expand. Contracting the belly pushes the diaphragm up which compresses the lungs and assists in eliminating the oxygen depleted air.
Here is a link to a 3-D video which shows how the diaphragm works.
3D view of the Diaphragm
Notice the breath. What message does it have for us?