TExES Physical Education EC-12 Practice Exam

Which explanation does not describe a physiological process of aerobic endurance?

1. The respiratory system supplies oxygen to the blood.

2. The musculoskeletal system conditions the heart to remove lactic acid.

3. The circulatory system transports blood to muscles.

4. The respiratory system efficiently takes air into the body.

The correct answer is: The musculoskeletal system conditions the heart to remove lactic acid.

The explanation that indicates the musculoskeletal system conditions the heart to remove lactic acid does not accurately describe a physiological process of aerobic endurance. Aerobic endurance primarily involves the coordinated efforts of the respiratory, circulatory, and muscular systems to utilize oxygen efficiently and sustain prolonged physical activity. In aerobic endurance, the respiratory system is responsible for facilitating gas exchange—bringing in oxygen and expelling carbon dioxide. The circulatory system plays a vital role in transporting oxygen-rich blood from the lungs to vital organs and muscles. The muscular system, while certainly involved in aerobic exercises, does not directly condition the heart; rather, it utilizes the oxygen delivered by the circulatory system for energy during activities. Lactic acid is typically produced during anaerobic metabolism, which occurs when energy is generated without sufficient oxygen. While the body has mechanisms to clear lactic acid, it is primarily the role of the circulatory system, through improved blood flow and oxygenation, rather than a conditioning effect of the musculoskeletal system on the heart itself.