Question

when the volume of tbe lung expands, it creates a ____. This lower pressure inside the lung is the reason air enters the lung as the person inspires.

Answer 1

When the volume of the lung expands, it creates a _change in pressure in the chest cavity _. This lower pressure inside the lung is the reason air enters the lung as the person inspires.

When we inhale air ( inspiration) , the diaphragm and intercostal muscles contracts and expand the chest cavity. This expansion lowers the pressure in the chest cavity below the outside air pressure. Air then flows in through the airways (from high pressure to low pressure) and expands the lungs.

When we exhale air ( expiration), the diaphragm and intercostal muscles relax and the chest cavity gets smaller in size. The decrease in volume of the cavity increases the pressure in the chest cavity above the outside air pressure. Air from the lungs then flows out of the airways to the outside air. Thus this cycle then repeats with each breath.