Mammalian diving reflex

The diving reflex is a protective mechanism, which can be observed in all lung -breathing creatures on immersion (immersion) in water. By stimulation of the parasympathetic breathing is stopped ( " suspended " ), slows the heartbeat and blood circulation centralized ( "Blood Shift" ). So that the oxygen consumption is reduced to about the vital organs.

Trigger

The existence of a single trigger for the diving reflex is not proven; believed to play among other receptors on the skin near the nose and upper lip a role. Even cold water appears to enhance the reflex. The centralization of the cardiac pulmonary circulation can be partially explained by the compression of the extremities when entering the water., The partial pressures of oxygen and carbon dioxide in the blood affect the parasympathetic nervous system. The brain is given the information that the airway below the water surface are.

Discovery

Was discovered the diving reflex by the physiologist Paul Bert (1833-1886), who diagnosed bradycardia in Gründel ducks.

Application

While it is very strong in the newborn this reflex, it reduces itself within a few weeks after birth. Through regular contact with water, it reinforced again and can even be aware train (see apnea diving).

In sports swimming the pulse values ​​are significantly lower than for the same physical stress on land for this reason.

The diving reflex is also used for the so-called water birth. The newborn takes its first breath under water, but only when the facial skin no longer has any contact with water.