What are the events that occur during human inspiration?

1. The diaphragm contracts, moving downward and flattening.

2. The external intercostal muscles between the ribs contract, raising the ribs and the sternum upward and outward.

3. The volume of the thoracic cavity increases, causing air to rush in through the nose and mouth.

4. The lungs expand, filling the increased space in the thoracic cavity.

5. Air enters the alveoli and oxygen diffuses into the blood.