 Dear students, in this topic we shall discuss the respite responses of animals to diving. Many air breathing equate equate breeds, for example dolphins, whales and water birds, they go underwater for varying periods of time. This duration of submersions is termed as a dive. Diving animals have to come back to the surface after some time so that they can breathe. The time between breeds varies with the animals. For most divers, this time is around 10 to 20 minutes. This usually doesn't happen without breathing in the water. Diving animals are subjected to periods of hypoxia and anoxia when they are in the process of diving. Hypoxia means that oxygen is slightly available but anoxia means that oxygen is not available. The central nervous system of mammals cannot tolerate anoxia. It must be supplied with oxygen throughout the dive. Diving animals utilize oxygen stores in their lungs, blood and tissues to supply oxygen to critical tissues. Most diving animals have high hemoglobin as well as myoglobin content. Myoglobin stores oxygen in them which is useful for such periods of time. Oxygen is preferentially delivered to brain and heart. Blood flow to other organs is reduced and they use anaerobic metabolic pathways. The prolonged divers who have more time to understand, for example elephant seal, reduce metabolic rates and reduce oxygen requirements. During diving, another problem and another control is that animals do not exhalation during the process of diving. This is controlled by specialized receptors which detect the presence of water. They inhibit inspiration during a dive. Such receptors are situated in glottis, mouth and nose. When oxygen level decreases in blood and carbon dioxide level increases, ventilation is stimulated in divers. This is the same position. This type of response is not produced. It is because the inputs from chemotherapy receptors of kerotid and aortic bodies which are to increase the ventilation rate are ignored by the respite neurons in submerged state.