This is the action which takes place in the thorax which brings oxygen into your body and expels waste carbon dioxide from it.
The thorax is the upper part of your body and in it are the lungs. The diaphragm separates these from the digestive system in your abdomen. The rib cage protects the thorax and the intercostal muscles keep it airtight to maintain the pressure needed.
When you breathe, the diaphragm contracts, flattening and increasing the thoracic volume allowing the lungs to expand, drawing air into them. The ribs also move…