Diaphragm
The diaphragm is a thin skeletal muscle that sits at the base of the chest and separates the abdomen from the chest. It contracts and flattens when you inhale. This creates a vacuum effect that pulls air into the lungs. When you exhale, the diaphragm relaxes and the air is pushed out of lungs.
It also has some non-respiratory functions as well. The diaphragm increases abdominal pressure to help the body get rid of vomit, urine, and feces. It also places pressure on the esophagus to prevent acid reflux.
The phrenic nerve, which runs from the neck to the diaphragm, controls the movement of the diaphragm. (source)
Diaphragm Strengthening Exercises
It also has some non-respiratory functions as well. The diaphragm increases abdominal pressure to help the body get rid of vomit, urine, and feces. It also places pressure on the esophagus to prevent acid reflux.
The phrenic nerve, which runs from the neck to the diaphragm, controls the movement of the diaphragm. (source)
Diaphragm Strengthening Exercises