Diving reflex

Diving infant while baby swimming

The diving reflex is a protection mechanism in all lung breathing living beings when immersed ( immersion can be observed) in water. By stimulating the parasympathetic nervous system , breathing is brought to a standstill (" suspended "), the heartbeat slows down and the blood circulation is centralized (" bloodshift "). This reduces the consumption of oxygen on the organs essential for survival .

trigger

The existence of a single trigger for the diving reflex has not been proven; Presumably, among other things, receptors on the skin near the nose and upper lip play a role. Even cold water seems to reinforce the reflex. The centralization of the cardiovascular system can in part be explained by the compression of the extremities upon entering the water. The partial pressures of oxygen and carbon dioxide in the blood also influence the parasympathetic nervous system. The brain is given the information that the airways are below the surface of the water.

discovery

The diving reflex was discovered by the physiologist Paul Bert (1833–1886), who diagnosed bradycardia in ducks that were forming .

In Typee , Herman Melville describes how a few days old baby swims independently in a stream in 1842.

application

While this reflex is very pronounced in the newborn, it is already reduced within a few weeks after birth. Regular contact with water strengthens it again and can even be trained consciously (see apnea diving ).

For this reason, the heart rate values for sport swimming are significantly lower than for the same physical exertion on land.

The diving reflex is also used for the so-called water birth. The newborn does not take its first breath under water, but only when the facial skin is no longer in contact with water.

Individual evidence

↑ Christoph Walter Johann Heek: Investigations on the diving reflex in humans and on breath sizes when scuba diving. , Heinrich Heine University Düsseldorf, Medical Faculty, 2001, p. 44
↑ ^a ^b P. Radermacher, C.-M. Muth, Apnea diving - Physiology and Pathophysiology (PDF; 678 kB). In: German magazine for sports medicine , Vol. 53, No. 6/2002, p. 188
^ Herman Melville: Typee: a peep at Polynesian life . Penguin Books, New York 1996, ISBN 978-0-14-043488-0 , pp. 229 .

[1] Christoph Walter Johann Heek: Investigations on the diving reflex in humans and on breath sizes when scuba diving. , Heinrich Heine University Düsseldorf, Medical Faculty, 2001, p. 44

[P._Radermacher,_C.-M._Muth-2] P. Radermacher, C.-M. Muth, Apnea diving - Physiology and Pathophysiology (PDF; 678 kB). In: German magazine for sports medicine , Vol. 53, No. 6/2002, p. 188

[3] Herman Melville: Typee: a peep at Polynesian life . Penguin Books, New York 1996, ISBN 978-0-14-043488-0 , pp. 229 .