What is the pressure of inspiration?

Ans: a (Intrapleural) Ref: Ganong,22nd ed,p. 6651The main pressure in lung related to inspiration is intrapleural pressure.Intrapleural pressure.The pressure in the intrapleural space between the lungs and chest wall is intrapleural pressure.Intrapleural pressure changes from -2.5 to -6 mmHg during inspiration. During strong inspiratory effort it may reach up to -30 mmHg.Transpulmonary pressureIt is the difference between alveolar pressure and intrapleural pressure. It is the measure of elastic forces in the lungs.Alveolar pressure or intrapulmonary pressureIt is the pressure inside the lung alveoli. When no air flows the alveolar pressure is considered to be equal to the atmospheric pressure, i.e., 0 cm of water.During inspiration it decreases to -1 cm of water.During expiration it increases to+1 cm of water.