In What Order Does a Nerve Impulse Travel to Cause Inspiration?

What are the 3 phases of breathing?

Pulmonary ventilation consists of the process of inspiration (or inhalation), where air enters the lungs, and expiration (or exhalation), where air leaves the lungs.

Which nerves are involved in the process of inspiration?

The phrenic nerve is actually a pair of nerves, the right and left phrenic nerves, that activate contraction of the diaphragm that expands the thoracic cavity. Because the lungs are stuck to the thoracic cavity, this expands the lungs and thereby draws air into them.