diving reflex


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div·ing re·flex

a reflex by which immersing the face or body in water, especially cold water, tends to cause bradycardia and peripheral vasoconstriction; mean aortic pressure is little affected because the reduction in cardiac output tends to balance the increased peripheral resistance that reduces peripheral blood flow. Although relatively minor in most humans, the changes can be profound in some species of diving animal, for example, ducks and seals.

diving reflex

n.
A reflexive response to diving in many aquatic mammals and birds, characterized by physiological changes that decrease oxygen consumption, such as slowed heart rate and decreased blood flow to the abdominal organs and muscles, until breathing resumes. Though less pronounced, the reflex also occurs in certain nonaquatic animals, including humans, upon submersion in water.

diving reflex

a neural mechanism that produces an automatic change in the cardiovascular system when the face and nose are immersed in cold water. The heart rate decreases and the blood pressure remains stable or increases slightly, while blood flow to all parts of the body except the brain is reduced, thereby helping the body to conserve oxygen. The reflex occurs in humans and other mammals. It is sometimes used in the treatment of paroxysmal tachycardias. The reflex extends the duration of the viability of brain cells during apnea beyond the usual period of 5 to 10 minutes. For this reason, cardiopulmonary resuscitation should always be attempted in drowning victims regardless of their time under water.
The physiologic responses—apnoea, bradycardia, peripheral vasconstriction, increased arterial blood pressure—to hypoxia, which were first described in diving simulations of aquatic animals

div·ing re·flex

(dīv'ing rē'fleks)
A reflex by which immersing the face or body in water, especially cold water, tends to cause bradycardia and peripheral vasoconstriction; relatively minor in most humans.
References in periodicals archive ?
Kolkka's corner was headed goalwards by Kuivasto and although Carroll made a great diving reflex save he pushed the shot out to Hyypia who was lurking at the back post and he side-footed the ball home - doubling his tally against Northern Ireland having also scored four years ago in Helsinki.
A team of experts will then help them develop their gifts, whether it's a latent linguistic skill that means you can become fluent in a foreign language in a matter of months, or a diving reflex that allows you to plumb depths of 60 metres without scuba gear.
A Canadian company called Mammalian Diving Reflex - crazy titles, it seems, are a Wunderbar feature - has a project called Haircuts by Children.
The idea of dunking your baby's head in a pool may horrify some parents but babies are born with a natural diving reflex which makes them hold their breath underwater automatically.