Final answer:
The major environmental change faced during high altitude travel, such as from New Jersey to Denver, is Lower atmospheric pressure, which leads to lower oxygen partial pressure and reduced oxygen saturation of hemoglobin, potentially causing hypoxia.
Step-by-step explanation:
When an individual travels from New Jersey (sea level) to Denver, Colorado (5,280 feet), the major change in the environment they face with respect to respiration and gas exchange is c) Lower atmospheric pressure. At higher altitudes, even though the proportion of oxygen in the atmosphere remains constant at about 21%, the partial pressure of oxygen is reduced.
This means that oxygen molecules are less likely to cross the respiratory membrane and enter the blood, leading to lower hemoglobin saturation with oxygen. This can cause individuals to experience symptoms such as shortness of breath or hypoxia due to a suboptimal amount of oxygen being delivered to the body's tissues.
Individuals who reside at higher altitudes, such as those in Denver, develop adaptations like increased hemoglobin levels to cope with the lower oxygen availability. People who travel from sea level to higher altitudes may need to take time to acclimatize and increase their erythrocyte count, enhancing oxygen delivery to tissues.
Additionally, the body compensates for the lower oxygen levels by increasing urine output to concentrate erythrocytes in the blood, but it's important to maintain hydration. Visitors to high altitudes are often advised to drink more water to counteract dehydration and help with acclimatization.