What can cause a temporary increase in pulse rate?

• A. Dehydration
• B. Sleep
• C. Exercise
• D. Cold weather

Answer: (C)

A temporary increase in pulse rate is commonly associated with exercise. During physical activity, the body's demand for oxygen increases. To meet this need, the heart pumps more blood, leading to a higher pulse rate. This physiological response allows for improved delivery of oxygen and nutrients to the muscles while facilitating the removal of carbon dioxide and metabolic waste products.

Exercise stimulates the sympathetic nervous system, which releases adrenaline and other hormones that elevate heart rate and cardiac output. The extent of the increase in pulse rate can vary based on the intensity of the workout and the individual's fitness level.

In contrast, while dehydration can lead to an increased heart rate, especially in a more chronic sense, it does not typically cause a temporary increase during normal activities. Sleep acts to decrease the pulse rate as the body enters a state of rest, and cold weather generally leads to vasoconstriction, which can lower heart rate as blood vessels constrict to conserve body heat.