What response does the body exhibit when oxygen levels in the blood are low?

• A. Decreased heart rate and increased blood pressure
• B. Increased heart rate and may increase respiratory rate
• C. Stable heart rate and decreased respiratory rate
• D. Complete cessation of breathing

Answer: (B)

When oxygen levels in the blood are low, the body responds by increasing the heart rate and may also increase the respiratory rate. This response is a vital compensatory mechanism to ensure that more oxygen is delivered to tissues and organs that require it for metabolism and function.

By increasing the heart rate, the body enhances blood circulation, allowing more oxygen-rich blood to reach areas that may be deprived of oxygen. Simultaneously, an increase in respiratory rate improves the intake of oxygen and facilitates the elimination of carbon dioxide, which can accumulate when oxygen levels drop. This coordinated response is critical for maintaining homeostasis and ensuring that the body can continue to function efficiently under conditions of low oxygen availability.