Body temperature maintenance

Structure. The stmctures of hides and skins are dependent on the needs of the animal and its environment. The functions of an animal s skin include protection from predators and infection, and maintenance of body temperature. The relative importance of these functions depends on the animal. Methods by which the skin accomplishes these functions is the same for most mammals. 

Fish show generally low HMO activities that are not strongly related to body weight. This may reflect a limited requirement of fish for metabolic detoxication they are able to efficiently excrete many compounds by diffusion across the gills. The weak relationship of HMO activity to body weight is probably because fish are poikilotherms and should not, therefore, have an energy requirement for the maintenance of body temperature that is a function of body size. In other words, the rate of intake of xenobiotics with food is unlikely to be strongly related to body size. 

The body is basically an isothermal system fine-tuned to 37°C (98.6°F). The skin has major responsibility in temperature maintenance. When the body is exposed to chilling temperatures that remove heat faster than the body s metabolic output can replace it, changes take place in the skin to conserve heat. Conversely, when the body becomes overheated, physiological processes come into play that lead to cooling. 

Le Chatelier s principle also applies to biology. Homeostasis is the tendency of a body system to remain in a state of equilibrium. Examples of homeostasis include the maintenance of body temperature (homeothermy) and the pH balance of blood. 

Energy expenditure comes in the form of basal metabolism, maintenance of body temperature, and physical exercise. 

Postsynaptic Hj- and Hj-receptors are responsible for a variety of processes in the CNS. Hi-receptors mediate the maintenance of wakeful states, while Hj- and Hj-receptors participate in the regulation of blood pressure, body temperature, fluid homeostasis, and pain sensation. Presynaptic Hj-receptors serve as feedback inhibitors of the release of histamine, norepinephrine, and other neurotransmitters. 

Life cannot be sustained without water. Water constitutes 45-73% of total human body weight. It is distributed in intracellular (55%) and extracellular (45%) compartments and provides a continuous solvent phase between body compartments. As the biological solvent, water plays a major role in all aspects of metabolism absorption, transport, digestion, and excretion of inorganic and organic substances as well as maintenance of body temperature. The unique properties of water are due to its structure. 

In the body, the energy derived from food is released as body heat and also used in the synthesis of ATP. The energy captured in ATP is then transformed into other forms, i.e., chemical (synthesis of new compounds), mechanical (muscle contraction), electrical (nerve activity), electrochemical (various ion pumps), thermal (maintenance of body temperature), and informational (base sequences in nucleic acids, amino acids in proteins). In general, the energy of food provides for the specific dynamic action of food, the maintenance of the body s basal metabolism, and the energy expenditure associated with various types of activity. 

Moreover, the term "breathable" implies that the fabric is actively ventilated. This is not the case. Breathable fabrics passively allow water vapour to diffuse through them yet still prevent the penetration of liquid water. Production of water vapour by the skin is essential for maintenance of body temperature. The normal body core temperature is 37°C, and skin temperature is between 33 and 35°C, depending on conditions. If the core temperature goes beyond critical limits of about 24°C and 45°C then death results. The narrower limits of 34°C and 42°C can cause adverse effects such as disorientation and convulsions. If the sufferer is engaged in a hazardous pastime or occupation then this could have disastrous consequences. 

The absorption of heat by a volatilizing liquid is utilized in the arts and in medicine for the production of cold (which is simply the absence of heat), in the manufacture of artificial ice, and in the production of lochl anesthesia by the ether-spray. The removal of heat from the botly in this way, by the evaporation of crspiration from the surface, la an important factor in the maintenance of the body temperature at a point consifiteot with life. 

Hodgkin s disease a malignant condition characterized by progressive enlargement of lymph nodes, spleen, and lymphoid tissues homeostasis maintenance of equilibrium with respect to the physiological functions of the body (stability of the metabolism, body temperature, pH value of the blood, blood pressure, etc.) by means of regulatory systems... 

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