Temperature deep body

Hyperbolic expansion The expansion of a fluid according to the law pV = Hypothalamus The temperature control center at the base of the brain, which regulates body temperature. Hypothermia The physiological state resulting when the deep core body temperature drops below 35 C. It results in vasoconstriction and shivering in an attempt to conserve body heat. 

Many animals hibernate during parts of the year, entering a state that is similar to a very deep sleep. But hibernation is more than simply a deep sleep. The animal s body temperature drops well below its normal range, the animal does not wake up for a long period of time, and its metabolism slows to the point that the animal does not need to eat or relieve itself during that period. 

Figure 7.9. Thermal stabilities of eye lens crystallins of differently thermally adapted vertebrates. The temperature (°C) at which 50% loss of secondary structure occurred, as measured using CD spectroscopy, is given as a function of the maximal body temperature of each species. Species (1) Pagothenia borchgrevinki (Antarctic fish), (2) Coryphaenoides armatus (deep-sea fish), (3) Coryphaen-oides rupestris (deep-sea fish),...

C The deep human body temperature of a healthy person remains constant at 37°C while the lempetature and the humidity of the environment change with time. Discuss the heat transfer mechanisms between the human body and the environment both in summer and winter, and explain how a per son can keep cooler in summer and wamier in winter. 

Consider a person standing in a room at 20°C with an exposed surface area of 1.7 m. The deep body temperature of the human body is 37 C, and the thermal conductivity of the human tissue near the skin is about 0.3 W/m C. The body is losing heat at a rate of 150 W by natural convection and radiation to the surroundings. Taking the body temperature 0,5 cm beneath the skin to be 37°C, determine the skin temperature of the person. Answer 35.5 C... 

Fixation by vascular perfusion ensures rapid access and even distribution of fixative in the tissue. It is usually performed via the heart, i.e., as a transcardial perfusion, under deep anesthesia. Details of this procedure depend on the species (e.g., cardiac anatomy, body temperature, optimal anesthetic), and it is outside the scope of this chapter to treat this issue in detail. For most invertebrate preparations, vascular perfusion is not necessary, or is even impossible to perform. 

Thermal challenges are met in several ways. Blood sent to the limbs and blood returning from the limbs are normally conveyed by arteries and veins in close proximity deep inside the limb. This tends to conserve heat by countercurrent heat exchange between the arteries and veins. Thermal stress causes blood to return via surface veins rather than deep veins. Skin surface temperature increases and heat loss by convection and radiation also increases. In addition, vasodilation of cutaneous blood vessels augments surface heat loss but puts an additional burden on the heart to deliver added blood to the skin as well as the muscles. Heart rate increases as body temperature rises. 

Minors, D. S., Waterhouse, J. M. (1985). Circadian rhythms in deep body temperature, urinary excretion and alertness in nurses on itight work. Ergonomics, 28, 1523-1530. 

A very serious and often fatal condition resulting from breakdown of thermoregulatory mechanisms during exposure to high temperature environments. It is characterized hy extremely high deep-body temperature and an absence of sweating. Treatment consists of rapid cooling in an ice bath. 

Exposure to extreme environments continuously may require medical monitoring. One aspect of such monitoring is continuously measuring the deep body temperature. There must be someone in place who can get a worker out of the extreme condition if the deep body temperature approaches or reaches 38 °C. In addition, medical monitoring may involve continuous measurement of heart and respiratory rates, and sweat rate. Visual observation may be part of medical monitoring. A worker in an extreme environment should have rescue and recovery equipment. There must be an emergency plan that includes a rescue from danger. 

What maximum deep body temperature should not be exceeded when someone works in hot environments ... 

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