Final answer:
During inspiration, the air is humidified and heated to 37℃ to reach 100% humidity. The process results in the air being saturated with water vapor, conforming to body temperature, and aiding in respiratory efficiency and protection of lung tissue.
Step-by-step explanation:
During inspiration, the air is humidified and warmed up to 37℃ saturated with water vapor. This process occurs because the air that enters the lungs must be brought to body temperature and 100% humidity before it reaches the sensitive tissue of the alveoli. When air is inhaled, it passes through the nasal passages, pharynx, and trachea before entering the lungs. This airway passage allows the inhaled air to be humidified by water vapor from the mucous membranes and warmed by the body's heat.
The saturation vapor pressure of water at 37℃ is approximately 6.31×10³ N/m², and the maximum amount of water vapor air can hold at this temperature is roughly 44 g/m³.
As the air is exhaled, it can carry away up to 4.00×10² g of water per 2.00 L of air, representing a heat transfer due to the heat required to evaporate that amount of water from the respiratory surfaces.