AP BIOLOGY

Detailed explanation-1: -The process of mechanical ventilation is regulated by the brain to physically move air in and out of the lungs so that oxygen and carbon dioxide can be exchanged with atmospheric air. The movement of air is the result of positive and negative pressure differences created within the thoracic cavity.

Detailed explanation-2: -Diffusion is the spontaneous movement of gases, without the use of any energy or effort by the body, between the alveoli and the capillaries in the lungs. Perfusion is the process by which the cardiovascular system pumps blood throughout the lungs.

Detailed explanation-3: -Pulmonary ventilation is commonly referred to as breathing. It is the process of air flowing into the lungs during inspiration (inhalation) and out of the lungs during expiration (exhalation). Air flows because of pressure differences between the atmosphere and the gases inside the lungs.

Detailed explanation-4: -Gas exchange between water and atmosphere is the product of a gas exchange rate K (1/d) and oxygen deficit Odef, which is the difference between O2 concentration in water at saturation for a given temperature and atmospheric pressure, and measured O2 concentration in the water.