Final answer:
The respiratory system responds to increased oxygen demand by increasing the breathing rate, red blood cell production, and dilating bronchioles to optimize oxygen uptake and CO2 removal.
Step-by-step explanation:
The respiratory system of an individual may respond to challenges such as increased demand for oxygen during exercise or adaptation to high altitude in several ways. First, there may be an increased breathing rate to facilitate more oxygen intake and carbon dioxide expulsion. Secondly, the body might increase red blood cell production to boost the oxygen-carrying capacity of the blood.
Lastly, there would be dilation of bronchioles to reduce resistance in the airways and allow more air to flow in and out of the lungs. These adjustments help in efficiently meeting the oxygen requirements of the body under stress or in different environmental conditions.