What are two kinds of muscle involved wth breathing?

* Diaphragm: The diaphragm is a large, dome-shaped muscle that separates the chest cavity from the abdominal cavity. It contracts and relaxes to pull air in and out of the lungs.

* Intercostal muscles: The intercostal muscles are located between the ribs. They contract and relax to help move the ribs up and down, which changes the volume of the chest cavity and pulls air in and out of the lungs.