Biological Systems MCAT Practice Exam

What happens during hypoxia?

1. There is an inadequate supply of blood

2. There is an inadequate supply of oxygen

3. There is excessively high blood flow

4. There is a regulation of hormone secretion

The correct answer is: There is an inadequate supply of oxygen

During hypoxia, there is an inadequate supply of oxygen to the tissues and organs of the body. This condition can occur even if blood flow is adequate; it specifically refers to the deficiency of oxygen in the environment or the body's inability to utilize the oxygen that is present. Hypoxia can result from various factors, including high altitudes where the partial pressure of oxygen is lower, respiratory diseases that impair gas exchange, or conditions such as anemia where the blood's capacity to carry oxygen is diminished. The body's response to hypoxia can lead to a series of physiological changes aimed at compensating for the lack of oxygen, such as increased heart rate and increased breathing rate. These adaptations help to deliver more oxygen to tissues despite the hypoxic conditions. Understanding hypoxia is crucial as it can affect cellular metabolism and lead to further complications if not addressed.