Question

Explain the changes in the pressures during inhalation and exhalation as it compares to outside of the body, and why this drives ventilation.

a) During inhalation, the intrapulmonary pressure decreases below atmospheric pressure, while during exhalation, it increases above atmospheric pressure. This pressure difference facilitates air movement into and out of the lungs, driving ventilation.
b) During inhalation and exhalation, the pressures remain constant inside and outside the body, having no effect on ventilation.
c) Inhalation causes an increase in intrapulmonary pressure, and exhalation results in a decrease in pressure, both in relation to atmospheric pressure, promoting ventilation.
d) Inhalation and exhalation have no effect on pressure changes, as ventilation is primarily controlled by the diaphragm and chest muscles.

Answer 1

Pulmonary ventilation involves the process of inhalation and exhalation. During inhalation, the diaphragm and intercostal muscles contract, lowering the pressure within the lungs and causing air to enter. During exhalation, the diaphragm and intercostals muscles relax, increasing the pressure within the lungs and forcing air out.

Step-by-step explanation:

Pulmonary ventilation consists of the process of inspiration (or inhalation), where air enters the lungs, and expiration (or exhalation), where air leaves the lungs. During inspiration, the diaphragm and external intercostal muscles contract, causing the rib cage to expand and move outward, and expanding the thoracic cavity and lung volume. This creates a lower pressure within the lung than that of the atmosphere, causing air to be drawn into the lungs. During expiration, the diaphragm and intercostals relax, causing the thorax and lungs to recoil. The air pressure within the lungs increases to above the pressure of the atmosphere, causing air to be forced out of the lungs. However, during forced exhalation, the internal intercostals and abdominal muscles may be involved in forcing air out of the lungs.