Final answer:
Negative intrapleural pressure is created by the tendency of the chest wall to recoil outward, causing the intrapleural pressure to drop and air to be drawn into the airways. Negative intrapleural pressure is created by the tendency of the chest wall to recoil outward and the lungs to recoil inward.
Step-by-step explanation:
Negative intrapleural pressure is created by the tendency of the chest wall to recoil outward. When the chest wall expands outward, the intrapleural pressure drops, and air is drawn into the airways. Negative intrapleural pressure is created by the tendency of the chest wall to recoil outward and the lungs to recoil inward. The intrapleural pressure is the pressure within the pleural cavity, the space between the visceral and parietal pleurae. The negative intrapleural pressure is essential for maintaining the expansion of the lungs and keeping them in close contact with the chest wall.
The chest wall has a natural tendency to expand outward due to the elasticity of the ribcage, while the lungs have a tendency to recoil or collapse inward due to their inherent elastic properties. These opposing forces result in a negative intrapleural pressure, which helps to keep the lungs inflated and allows for the passive movement of air into the lungs during normal breathing. This negative pressure is critical for lung function and maintaining respiratory mechanics.