Diving Reflex

Definition: A set of complex physiological adaptations some marine mammals have evolved that enables them to dive to great depths for extended periods of time. The diving reflex in marine mammals such as whales redirects blood flow primarly to the heart, brain, and skeletal muscles. Also, when a whale surfaces, it releases the large amount of built-up carbon dioxide by quickly exhaling a large breath through its spout. Finally, during a dive, the whale's heart rate slows to reduce the rate of oxygen depletion. This reflex also enables sea lions and seals to stay underwater for 30 minutes or longer.