HUMAN NUTRITION

Detailed explanation-1: -C. When the lungs expand, they fill with air from the atmosphere. This is correct because the lungs expand to create a vacuum, which draws air into the lungs.

Detailed explanation-2: -This space is taken up by the lungs when we inhale. Hence, the correct statement is that air enters into the lungs because the chest expands.

Detailed explanation-3: -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-4: -During inspiration, the diaphragm and external intercostal muscles contract, causing the rib cage to expand and move outward, and expanding the thoracic cavity and lung volume. This creates a lower pressure within the lung than that of the atmosphere, causing air to be drawn into the lungs.