Mammals including man are endotherms and maintain constant body temperature with in a narrow tolerable range of about 36-37.5 centigrade under any condition. It is achieved by following ways:
Shivering thermo genesis: Increased muscle contraction or shivering produce more heat.
Non-shivering thermo genesis: Oxidation of carbohydrates by hormones like thyroid hormones generates heat. Brown fat also produces a good source of heat production.
Vasodilatation: Increased blood flow to skin causes loss of heat by radiation and evaporation.
Regulation of heat exchange in cold temperature environment:
It is regulated by the following steps: Vasodilatation(increased blood flow) and vasoconstriction(decreased blood flow) regulate regional temperature differences with in animal e.g. in a cold dry, arms and legs may have several degree low temperature than the trunk to maintain normal temperature in vital body organs.
Most land mammals raise their furs trap the thick layer of still air which severe as insulator.
Human conserve heat due to the presence of layer of fat beneath the skin which insulate the body.
Marine mammals e.g. whale and seal conserve heat even in much colder water due to presence of thick layer of insulating fat called as blubber under the skin.
Regulation of heat exchange in warm temperature environment:
Marine mammal's loss heat in the warmer water through the skin where it is brought by blood circulation.
Terrestrial mammals lose heat by evaporation cooling. In this mechanism, sweat glands play important role in producing sweat.
Bats use saliva and urine to loss excessive heat.
Shivering thermo genesis: Increased muscle contraction or shivering produce more heat.
Non-shivering thermo genesis: Oxidation of carbohydrates by hormones like thyroid hormones generates heat. Brown fat also produces a good source of heat production.
Vasodilatation: Increased blood flow to skin causes loss of heat by radiation and evaporation.
Regulation of heat exchange in cold temperature environment:
It is regulated by the following steps: Vasodilatation(increased blood flow) and vasoconstriction(decreased blood flow) regulate regional temperature differences with in animal e.g. in a cold dry, arms and legs may have several degree low temperature than the trunk to maintain normal temperature in vital body organs.
Most land mammals raise their furs trap the thick layer of still air which severe as insulator.
Human conserve heat due to the presence of layer of fat beneath the skin which insulate the body.
Marine mammals e.g. whale and seal conserve heat even in much colder water due to presence of thick layer of insulating fat called as blubber under the skin.
Regulation of heat exchange in warm temperature environment:
Marine mammal's loss heat in the warmer water through the skin where it is brought by blood circulation.
Terrestrial mammals lose heat by evaporation cooling. In this mechanism, sweat glands play important role in producing sweat.
Bats use saliva and urine to loss excessive heat.