In: Anatomy and Physiology
Briefly differentiate between atmospheric pressure, intrapulmonary pressure, and intrapleural pressure. Which of these is always negative in a healthy individual during normal breathing? What happens if intrapleural pressure becomes equal to atmospheric pressure? The contraction of the diaphragm and the external intercostal muscles begins inspiration. Explain exactly what happens, in terms of volume and pressure changes in the lungs, when these muscles contract. What is the functional significance of the pleural fluid during inspiration?