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The immediate shock of the cold causes involuntary inhalation, which if underwater can result in drowning. The cold water can also cause heart attack due to vasoconstriction; [4] the heart has to work harder to pump the same volume of blood throughout the body, and for people with heart disease, this additional workload can cause the heart to ...
Supplementary oxygen administration is widely used in emergency and intensive care medicine and can be life-saving in critical conditions, but too much can be harmful and affects a variety of pathophysiological processes. Reactive oxygen species are known problematic by-products of hyperoxia which have an important role in cell signaling pathways.
Conversely, if the peripheral chemoreceptors are stimulated by hypoxia while the animal is breathing, the ventilation, heart rate and vasodilation of skeletal muscles is increased. [3] Oxygen consumption during a dive can be reduced by about 70%, attributed to anaerobic metabolism and probably also cooling of the body. [3]
Mitigation may be by supplementary oxygen, pressurisation of the habitat or environmental protection suit, or a combination of both. In all cases the critical effect is the raising of oxygen partial pressure in the breathing gas. [1] Room air at altitude can be enriched with oxygen without introducing an unacceptable fire hazard.
Mild bradycardia is caused by subjects holding their breath without submerging the face in water. [10] [11] When breathing with the face submerged, the diving response increases proportionally to decreasing water temperature. [8] However, the greatest bradycardia effect is induced when the subject is holding their breath with their face wetted ...
Liquid breathing is a form of respiration in which a normally air-breathing organism breathes an oxygen-rich liquid which is capable of CO 2 gas exchange (such as a perfluorocarbon). [ 1 ] The liquid involved requires certain physical properties, such as respiratory gas solubility, density, viscosity, vapor pressure and lipid solubility, which ...
Breathing pure oxygen significantly reduces the nitrogen loads in body tissues by reducing the partial pressure of nitrogen in the lungs, which induces diffusion of nitrogen from the blood into the breathing gas, and this effect eventually lowers the concentration of nitrogen in the other tissues of the body.
Dissolved oxygen levels required by various species in the Chesapeake Bay (US). In aquatic environments, oxygen saturation is a ratio of the concentration of "dissolved oxygen" (DO, O 2), to the maximum amount of oxygen that will dissolve in that water body, at the temperature and pressure which constitute stable equilibrium conditions.