The heat-regulating center is found in the
|
What is thermoregulation? Show Thermoregulation is a process that allows your body to maintain its core internal temperature. All thermoregulation mechanisms are designed to return your body to homeostasis. This is a state of equilibrium. A healthy internal body temperature falls within a narrow window. The average person has a baseline temperature between 98°F (37°C) and 100°F (37.8°C). Your body has some flexibility with temperature. However, if you get to the extremes of body temperature, it can affect your body’s ability to function. For example, if your body temperature falls to 95°F (35°C) or lower, you have “hypothermia.” This condition can potentially lead to cardiac arrest, brain damage, or even death. If your body temperature rises as high as 107.6°F (42 °C), you can suffer brain damage or even death. Many factors can affect your body’s temperature, such as spending time in cold or hot weather conditions. Factors that can raise your internal temperature include:
Factors that can lower your internal temperature include:
Your hypothalamus is a section of your brain that controls thermoregulation. When it senses your internal temperature becoming too low or high, it sends signals to your muscles, organs, glands, and nervous system. They respond in a variety of ways to help return your temperature to normal. When your internal temperature changes, sensors in your central nervous system (CNS) send messages to your hypothalamus. In response, it sends signals to various organs and systems in your body. They respond with a variety of mechanisms. If your body needs to cool down, these mechanisms include:
If your body needs to warm up, these mechanisms include:
If your internal temperature drops or rises outside of the normal range, your body will take steps to adjust it. This process is known as thermoregulation. It can help you avoid or recover from potentially dangerous conditions, such as hypothermia. As in other mammals, thermoregulation in humans is an important aspect of homeostasis. In thermoregulation, body heat is generated mostly in the deep organs, especially the liver, brain, and heart, and in contraction of skeletal muscles.[1] Humans have been able to adapt to a great diversity of climates, including hot humid and hot arid. High temperatures pose serious stress for the human body, placing it in great danger of injury or even death. For humans, adaptation to varying climatic conditions includes both physiological mechanisms resulting from evolution and behavioural mechanisms resulting from conscious cultural adaptations.[2][3] There are four avenues of heat loss: convection, conduction, radiation, and evaporation. If skin temperature is greater than that of the surroundings, the body can lose heat by radiation and conduction. But, if the temperature of the surroundings is greater than that of 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 surrounding temperature is higher than the skin temperature, anything that prevents adequate evaporation will cause the internal body temperature to rise.[4] During sports activities, evaporation becomes the main avenue of heat loss.[5] Humidity affects thermoregulation by limiting sweat evaporation and thus heat loss.[6] Humans cannot survive prolonged exposure to a wet-bulb temperature above 35 °C (95 °F). Such a temperature used to be thought not to occur on Earth's surface but has been recorded in some parts of the Indus Valley and Persian Gulf. Occurrence of conditions too hot and humid for human life is expected to increase in the future due to global warming.[7] Control system[edit]The core temperature of a human is regulated and stabilized primarily by the hypothalamus, a region of the brain linking the endocrine system to the nervous system,[9] and more specifically by the anterior hypothalamic nucleus and the adjacent preoptic area regions of the hypothalamus. As core temperature varies from the set point, endocrine production initiates control mechanisms to increase or decrease energy production/dissipation as needed to return the temperature toward the set point (see figure).[8] In hot conditions[edit]
In hot and humid conditions[edit]In general, humans appear physiologically well adapted to hot dry conditions.[11] However, effective thermoregulation is reduced in hot, humid environments such as the Red Sea and Persian Gulf (where moderately hot summer temperatures are accompanied by unusually high vapor pressures), tropical environments, and deep mines where the atmosphere can be water-saturated.[11][2] In hot-humid conditions, clothing can impede efficient evaporation.[3] In such environments, it helps to wear light clothing such as cotton, that is pervious to sweat but impervious to radiant heat from the sun. This minimizes the gaining of radiant heat, while allowing as much evaporation to occur as the environment will allow. Clothing such as plastic fabrics that are impermeable to sweat and thus do not facilitate heat loss through evaporation can actually contribute to heat stress.[6] In cold conditions[edit]
Uses of hypothermia[edit]Adjusting the human body temperature downward has been used therapeutically, in particular, as a method of stabilizing a body following trauma. It has been suggested that adjusting the adenosine A1 receptor of the hypothalamus may allow humans to enter a hibernation-like state of reduced body temperature, which could be useful for applications such as long-duration space flight.[12] [edit]The thermoregulatory sweat test (TST) can be used to diagnose certain conditions that cause abnormal temperature regulation and defects in sweat production in the body. To perform the test, the patient is placed in a chamber that slowly rises in temperature. Before the chamber is heated, the patient is coated with a special kind of indicator powder that will change in color when sweat is produced. This powder, when changing color, will be useful in visualizing which skin is sweating versus not sweating. Results of the patient’s sweat pattern will be documented by digital photography, and abnormal TST patterns can indicate if there is dysfunction in the autonomic nervous system. Certain differentials can be made depending on the type of sweat pattern found from the TST (along with history and clinical presentation) including hyperhidrosis, small fiber and autonomic neuropathies, multiple system atrophy, Parkinson disease with autonomic dysfunction, and pure autonomic failure.[13] Related diseases and syndromes[edit]
References[edit]
Where is the heatThe principal heat-regulating centre is located in the hypothalamus, a portion of the fore-brain.
Is the heatMuch like a thermostat regulates the temperature inside your home, the hypothalamus regulates your body temperature, responding to internal and external stimuli and making adjustments to keep the body within one or two degrees of 98.6 degrees.
Which part of the brain is principal heat regulation Centre?The principal heat-regulating centre is located in hypothalamus.
What is heat regulation called?Thermoregulation is a mechanism by which mammals maintain body temperature with tightly controlled self-regulation independent of external temperatures. Temperature regulation is a type of homeostasis and a means of preserving a stable internal temperature in order to survive.
|
