During the mammalian dive reflex, what happens to the heart rate?

During the mammalian dive reflex, the heart rate slows down to conserve energy. This reflex is a physiological response observed in mammals when they are submerged in water, and it serves several important functions. The reduction in heart rate, known as bradycardia, helps to minimize oxygen consumption and prioritize the oxygen supply to vital organs, particularly the brain and heart.

This conservation mechanism is especially crucial during prolonged periods underwater, allowing the animal to enhance its chances of survival by maintaining essential functions while reducing overall metabolic demand. As a result, it allows mammals to effectively manage their oxygen reserves during diving activities.

The options involving an increase in heart rate or acceleration to pump oxygen do not align with the physiological adaptations that occur during the dive reflex. The heart’s response is specifically aimed at prolonging the duration of the dive and enhancing survival.