PATHOLOGY

Detailed explanation-1: -Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarges. This contraction creates a vacuum, which pulls air into the lungs. Upon exhalation, the diaphragm relaxes and returns to its domelike shape, and air is forced out of the lungs.

Detailed explanation-2: -Diaphragm contracts, moves down and flattens during inhalation and diaphragm relaxes and curves upwards during exhalation. So, when diaphragm of man is completely dome shaped, it shows that beginning of expiration and end of inspiration.

Detailed explanation-3: -During expiration, the diaphragm relaxes, the cavity volume decreases, and the pressure rises. The lungs constrict as a result, and the air is driven out. A vacuum is created by this contraction. This causes air to be drawn into the lungs.

Detailed explanation-4: -When the lungs inhale, the diaphragm contracts and pulls downward. At the same time, the muscles between the ribs contract and pull upward. This increases the size of the thoracic cavity and decreases the pressure inside. As a result, air rushes in and fills the lungs.