Thermoregulation is the ability of an organism to maintain body temperature within certain limits, even when temperature surrounding is very different. This process is one aspect of homeostasis: a dynamic state of stability between the internal environment of animals and the external environment (the study of such processes in zoology has been called Ekofisiologi or physiological ecology)
thermoregulation in humans
As in other mammals, thermoregulation is an important aspect of human homeostasis. Most of the body heat generated in the internal organs, especially the liver, brain, and liver and in skeletal muscle contraction. Humans have been able to adapt to climate variability, including dry and hot humid heat. High temperatures cause serious stress for the human body, placing it in danger of injury or even death. For humans, the adaptation to various climatic conditions include physiological mechanisms as a byproduct of evolution, adaptation and development of conscious culture.
There are four paths of heat loss: convection, conduction, radiation, and evaporation. If the temperature is greater than the surrounding skin, the body can lose heat through radiation and conduction. But if the ambient temperature is greater than the skin, the body actually gains heat by radiation and conduction. In such conditions, the only means by which the body can rid itself of heat is by evaporation. So when the ambient temperature is higher than skin temperature, whatever that prevent adequate evaporation will cause the internal body temperature to rise. During sporting events, evaporation becomes the main street of heat loss. Humidity influence thermoregulation by limiting evaporation of perspiration and thus heat loss.
• sweat glands under the skin to sweat (fluid containing mostly water with some dissolved ions) is moving to channel sweat, sweat through the pores and the skin surface. This causes heat loss through evaporative cooling, but many important water is lost.
• The feathers lying on the skin, preventing heat from being trapped by a layer of still air between the hairs. This is due to the small muscles beneath the skin surface called pili spinae muscles attached to hair follicles relax so that they do not erect. This hair flat increase air flow in addition to the increased skin heat loss by convection. When the ambient temperature on core body temperature, sweating is the only way for humans to physiological heat loss.
• arteriolar vasodilation occurs, this is the process of arterial wall smooth muscle relaxation allows increased blood flow through arteries. This shift of blood to the superficial capillaries in the skin increasing heat loss by convection and conduction.
• sweat stop production.
• The muscles of the minutes under the skin surface called pili spinae muscles (attached to individual hair follicle) contract (piloerection), lifting up the hair follicles. This makes our hair stand on end which acts as an insulating layer, trapping heat. This is what also causes goose bumps because people do not have very much hair and contracted muscles can easily be seen.
• arterioles carry blood to the superficial capillaries beneath the skin can shrink (constrict), thereby rerouting blood from the skin and into the core is warmer than the body. This prevents blood from losing heat to the environment and also prevents the core temperature decreases further. This process is called vasoconstriction. It is impossible to prevent all loss of heat from the blood, just to reduce it. In very cold conditions excessive vasoconstriction causing numbness and pale skin. Frostbite only occurs when water in the cell starts to freeze, this destroys the cells causing damage.