What happens to breathing rate if air pressure decreases?

When air pressure decreases, the partial pressure of oxygen in the air also drops. This reduced availability of oxygen leads to a lower amount of oxygen entering the lungs during inhalation. To compensate for the decreased oxygen availability, the body responds by increasing the breathing rate. This adjustment helps to enhance gas exchange and improve oxygen intake, ensuring that the body's tissues still receive an adequate supply of oxygen despite the low atmospheric pressure.

In higher altitudes, for example, the air pressure is lower, prompting individuals to breathe more rapidly to maintain oxygen levels necessary for proper physiological function. Therefore, under conditions of decreasing air pressure, an increased breathing rate is the body's adaptive mechanism.