How do the cardiovascular and respiratory systems collaborate during exercise?

• A. They decrease oxygen delivery to the muscles
• B. They work together to increase oxygen delivery and carbon dioxide removal from muscles
• C. They slow down blood flow to conserve energy
• D. They regulate digestive functions

Answer: (B)

During exercise, the cardiovascular and respiratory systems work closely together to ensure that the body's tissues receive adequate oxygen and that carbon dioxide is efficiently removed. This collaboration is crucial because muscles require more oxygen to produce energy through aerobic metabolism during physical activity. As exercise intensity increases, the respiratory rate elevates, allowing for more oxygen to be inhaled and delivered to the bloodstream. Concurrently, the heart increases its output by pumping more blood to the active muscles, which enhances oxygen delivery.

Additionally, the increased blood flow helps in carrying carbon dioxide—a byproduct of muscular metabolism—away from the muscles to the lungs, where it can be exhaled. This synergistic action allows the body to maintain homeostasis during the increased metabolic demands of exercise. The other options suggest mechanisms that are contrary to the physiological responses of the body during physical activity, such as decreasing oxygen delivery or slowing down blood flow, which do not support the body's needs during exercise.