Question

inspiration begins as...
multiple choice
the lungs contract
the diaphragm contracts
the lungs expand
the diaphragm relaxes

Explanation:

During inspiration (inhalation), the diaphragm contracts. This contraction causes the diaphragm to move downward, increasing the volume of the thoracic cavity. As a result, the pressure inside the thoracic cavity decreases relative to the atmospheric pressure, and air flows into the lungs. The lungs expand as they fill with air, but the initial event that starts inspiration is the contraction of the diaphragm. The lungs contracting is part of expiration (exhalation), and the diaphragm relaxing is also part of expiration.

Answer:

The diaphragm contracts