What kind of pressure is created in the lungs during inhalation?

During inhalation, a negative pressure is created in the lungs, which facilitates the influx of air. When the diaphragm and intercostal muscles contract, the thoracic cavity expands. This increases the volume inside the lungs, leading to a decrease in pressure within the lung cavities compared to the atmospheric pressure outside. As a result, air is drawn into the lungs to equalize the pressure difference.

This mechanism of negative pressure is crucial for effective respiration, allowing oxygen-rich air to enter the lungs while enabling carbon dioxide to be expelled during exhalation when the pressure inside the lungs becomes greater than the atmospheric pressure. Understanding this principle is fundamental in grasping how the respiratory system functions and the role of pressures in breathing.