Question

what happens to cardiac output during physical activity? remains constant throughout physical activity increases due to decreased oxygen demand decreases to conserve energy increases to meet the bodys increased oxygen demands decreases due to decreased oxygen demand

Explanation:

During physical activity, the body's cells need more oxygen to produce energy (through cellular respiration). The heart responds by increasing cardiac output (the volume of blood pumped by the heart per minute). This is because a higher cardiac output allows for more oxygen - rich blood to be delivered to the working muscles.

• Option 1: Remaining constant is incorrect as the body's oxygen demand changes during physical activity, and the heart adjusts.
• Option 2: Increased cardiac output is due to increased, not decreased, oxygen demand.
• Option 3: Decreasing to conserve energy is wrong because physical activity requires more energy, not less.
• Option 5: Decreasing due to decreased oxygen demand is incorrect as oxygen demand increases during physical activity.

Answer:

Increases to meet the body's increased oxygen demands