What is the effect of gravity on intrapleural pressure?

Microgravity causes a decrease in lung and chest wall recoil pressures as it removes most of the distortion of lung parenchyma and thorax induced by changing gravity field and/or posture.

Why is the intrapleural pressure more negative at the apices than at the bases of the lungs?

When the parietal pleura expands with the chest the negative intrapleural pressure causes the visceral pleura to be pulled with it. The weight of the lung parenchyma results in intrapleural pressure being more negative at the apex than the base.

What is the difference between the intrapulmonary and intrapleural pressures?

The force exerted by gases within the alveoli is called intra-alveolar (intrapulmonary) pressure, whereas the force exerted by gases in the pleural cavity is called intrapleural pressure.

How does the intrapleural pressure influence the distribution of gas movement?

Pulmonary System The dome of the diaphragm extends upward into the thoracic space. During inspiration, the diaphragm contracts and flattens, expanding the volume of the thoracic space. The subsequent drop in interpleural pressure causes the lungs to expand, pulling the lungs downward toward the abdominal space.

Why is intrapleural pressure less negative at the base?

These two sides are continuous and meet at the hilum of the lung. As a result of gravity, in an upright individual the pleural pressure at the base of the lung base is greater (less negative) than at its apex; when the individual lies on his back, the pleural pressure becomes greatest along his back.

Why does intrapleural pressure becomes more negative during inspiration?

As the intrapleural and alveolar pressure become increasingly negative due to the expansion of the chest cavity during inspiration, air from the atmosphere flows into the lungs which allow the lung volume to increase and participate in gas exchange.

Why is intrathoracic pressure negative?

Why is the intrapleural pressure Subatmospheric?

Intra-pleural pressure is sub-atmospheric. This is due to the recoil of the chest and lungs away from each other. Müller’s maneuver can temporarily but significantly decrease the intrapleural pressure.

Why is intrapleural pressure negative during inspiration?

Why does intrathoracic pressure decrease during inspiration?

Inspiration drops intrathoracic pressure, dilates the thoracic vena cava, and acutely decreases atrial filling. Cardiac output falls, and consequently arterial pressure falls. The drop in arterial pressure reduces stretch on the arterial baroreceptors, causing a reflex increase in heart rate.

Why does intrapleural pressure become more negative during inspiration?

During inspiration, the diaphragm and external intercostal muscles contract, increasing the volume of the thoracic cavity. This causes the intrapleural pressure to become more negative, which increases the transpulmonary pressure, causing the lungs to expand.