Temperature, body

Animals that are described as warm blooded, or endothermic, maintain a constant internal temperature, even when exposed to extreme temperatures in their environment. In mammals, this internal temperature is about 97°F (36°Q, while in birds, it is warmer, around 108°F (42°Q. 

Warm-blooded animals have developed several physiological and behavioral modifications that help regulate body temperature. Since their bodies generate heat by 

Heart rate and rate of respiration in warm-blooded animals does not depend on the temperature of the surroundings. For this reason, they can be as active on a 

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Acetylsalicylic acid is largely used in medicine as an analgesic (t.e., for removing pain) and as an antipyretic (i.e., for reducing the body temperature). 

In chocolate, cocoa butter is the continuous phase. The characteristic meltabiUty of cocoa butter constitutes a puzzle in chemical stmcture and poses difficulty in replacement cocoa butter has a sharp melting point at body temperature. 

Sohd fats may show drastically different melting behavior. Animal fats such as tallow have fatty acids distributed almost randomly over all positions on the glycerol chain. These fats melt over a fairly broad temperature range. Conversely, cocoa has unsaturated fatty acids predominantly in the 2 position and saturated acids in the 1 and 3 positions. Cocoa butter is a brittle sohd at ambient temperature but melts rapidly just below body temperature. 

Heat. Personal monitoring of the environmental conditions which impose a heat stress on a worker is impractical, so fixed station measurement of such parameters as wet bulb globe temperature are usually made (see Temperature measurements). These stations are carefully selected so that the results, plus worker location and workload data, can be combined to yield an overall heat stress estimate. Heat strain, the effect on the human, can be estimated from core body temperature, but this is usually only a research tool. 

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. 

Antiperspirants. Aluminum chlorohydrate, widely used as an antiperspirant (32), came into usage in the early 1940s (2). The mechanism for antiperspirant activity is the formation of an obstmctive aluminum hydroxide plug within the sweat gland duct (17). When aluminum chlorohydrate at body temperature is simultaneously diluted with sweat and exposed to the higher pH on the skin, insoluble aluminum hydroxide rapidly forms. 

Thorotrast (colloidal Th02) was once used as a radiopaque agent in medicine (see Radiopaques). Its injection in a dose of 2.0—15.0 g caused rises in body temperature, nausea, and injury to tissues at the injection site, followed by anemia, leukopenia, and impairment of the reticuloendothehal system. After intravenous adrninistration, thorotrast particles are taken up by reticuloendothehal cells of the fiver and spleen. Thorotrast is virtually not eliminated from the body (91). Between 1947 and 1961, 33 cases of cancer of the fiver, larynx, and bronchi and sarcoma of the kidneys, developing from 6 to 24 years after thorotrast administering, have been described in the literature (92). 

Live attenuated vaccines for RSV are also being developed. Most of these vaccine candidates are derived from cold adaptation, by passing the vims at progressingly lower temperatures than human body temperatures. However, other means of mutagenesis have been used to generate vaccine candidates (72). Several clinical trials of these vaccines are also in progress (73,74). 

Composition and Properties. Cocoa butter is a unique fat with specific melting characteristics. It is a soHd at room temperature (20°C), starts to soften around 30°C, and melts completely just below body temperature. Its distinct melting characteristic makes cocoa butter the preferred fat for chocolate products. 

In order to avoid conception, abstinence from sexual intercourse during the fertile period of the menstmal cycle must be practiced (77,104). It has been deterrnined that the fertile period in women occurs before menstmation (105,106), and formulas have been developed to determine the fertile and infertile days of the menstmal cycle. Ovulation has been linked to a cycHc shift in basal body temperature (107), which can be used retrospectively to determine the time of ovulation. 

The egg shell is 94% calcium carbonate [471-34-17, CaCO, 1% calcium phosphate [7758-23-8] and a small amount of magnesium carbonate [546-93-0]. A water-insoluble keratin-type protein is found within the shell and in the outer cuticle coating. The pores of the shell allow carbon dioxide and water to escape during storage. The shell is separated from the egg contents by two protein membranes. The air cell formed by separation of these membranes increases in size because of water loss. The air cell originally forms because of the contraction of the Hquid within the egg shell when the temperature changes from the body temperature of the hen at 41.6°C to a storage temperature of the egg at 7.2°C. 

Besides behavior and blood pressure, catecholamine neurons also have important roles in other brain functions. Regulation of neuroendocrine function is a well-known action of catecholamines for example, DA agonists reduce semm prolactin concentration, especially in conditions of hypersecretion. Ingestive behavior can be modulated by brain catecholamines, and some appetite-suppressing dmgs are beheved to act via catecholaminergic influences. Catecholamines also participate in regulation of body temperature. 

Total Radiation Pyrometers In total radiation pyrometers, the thermal radiation is detec ted over a large range of wavelengths from the objec t at high temperature. The detector is normally a thermopile, which is built by connec ting several thermocouples in series to increase the temperature measurement range. The pyrometer is calibrated for black bodies, so the indicated temperature Tp should be converted for non-black body temperature. 

Humans seek and want thermal comfort, even at work in industrial settings. Clothing, activities, posture, location, and shelter are chosen, adjusted, altered, and sought consciously and unconsciously to reduce discomforts and enable us to focus more on the other tasks of life. Discomfort can contribute to mistakes, productivity decreases, and industrial accidents. " Thermal discomfort results from the physiological strain of thermoregulation. The strain can be in the form of altered body temperatures, sweating and excessive skin moisture, muscle tension and stiffness, shivering, and loss of dexterity. A small... 

Humans and the other warm-blooded animals have developed thermoregulatory systems to carefully control body temperature to levels that enable them to function and survive effectively. In general, thermal comfort occurs when the physiological effort to control body temperature is minimized for the activity. Table. 5.1... 

HOT Tblood flow to. skin (vasodilation), heart rate T, sweating T, skin moisture T, body temperatures T, metabolism T... 

NEUTRAL comfort, minimized effort, (mean body temperature). 36.2 C... 

COLD Xblood flow to skin (vasocoiistriction, muscle tension and shivering t, body temperatures X, metabolism T... 

To maintain proper body temperatures (T), metabolic energy (M) must be continuously transferred to the environment. 

The body temperature limits for health in terms of internal or core temperature are fairly limited. The limits are basically related to the function of nervous tissue. Body temperatures around 28 °C or less can result in cardiac fibrillation and arrest. Temperatures of 43 °C and greater can result in heat stroke, brain damage, and death. Often, too high a temperature causes irreversible shape changes to the protein molecules of nervous tissue. That is, cooling overheated tissue to normal temperatures may not restore its original function. 

Body temperatures are primarily sensed by temperature sensors in the hypothalamus near the center of the brain. Arterial blood flowing over and near the hypothalamus gives it information about the average thermal condition of... 

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