MICROANATOMY

Detailed explanation-1: -The second phase is called expiration, or exhaling. When the lungs exhale, the diaphragm relaxes, and the volume of the thoracic cavity decreases, while the pressure within it increases. As a result, the lungs contract and air is forced out.

Detailed explanation-2: -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-3: -Abdominal Muscles: Any number of muscles in the abdomen that exert pressure on the diaphragm from below to expand it, which in turn contracts the thoracic cavity, causing forced exhalation.

Detailed explanation-4: -In exhalation, the diaphragm moves upward and the chest wall muscles relax, causing the chest cavity to get smaller and push air out of respiratory system through the nose or mouth.

Detailed explanation-5: -During expiration, the relaxation of the diaphragm and elastic recoil of tissue decreases the thoracic volume and increases the intraalveolar pressure. Expiration pushes air out of the lungs.