When the lungs inhale, the changes of lung volume and air pressure are _ _ _ _ _ _

Respiratory movement refers to the rhythmic expansion and contraction of the human chest, including inhalation and exhalation. When inhaling, when the intercostal muscles contract, the ribs move upward and outward, which increases the anterior-posterior diameter and left-right diameter of the chest cavity. At the same time, the diaphragm contracts and the top of the diaphragm descends, which increases the upper and lower diameter of the thorax, increases the volume of the thorax, and expands the lungs, resulting in an increase in the volume of the lungs. The air pressure in the lungs is lower than the outside atmospheric pressure, and the outside air passes through.

So the answer is: when the intercostal muscle contracts, the ribs move upward and outward, which increases the anterior and posterior diameter and the left and right diameter of the thorax. At the same time, the diaphragm contracts and the top of the diaphragm drops, which increases the upper and lower diameter of the thorax, increases the thoracic volume, and expands the lung, resulting in an increase in lung volume. The air pressure in the lungs is lower than the outside atmospheric pressure, and the outside air enters the lungs through the respiratory tract to complete the inhalation process.