Experiment on Regulation of Body Temperature

Experiment on Regulation of Body Temperature

Theory: Human is HOMEOTHERMIC : with wide fluctuations in  environmental temperature, body temperature is maintained maintained within a narrow range. Old term: Warm –   blooded.  Poikilothermic Poikiloth ermic organism (such (such as the frog): body temperature fluctuates over a considerable wide range. Old term: Cold – blooded.  Human is Endothermic: metabolic reactions within the  body are the the sources sources of Body Temperature. Temperature. Core Temperature: temperature of deep tissues. The change  is ± 1° F; ± 0.6°C. Tolerable Fluctuation in Environmental temperature: as low as 55° F ; and as high as 130° F.  Human body temperature could be lowered down to 2124°C (70-75°F) without permanent illness. Such Hypothermia is useful for specific surgery. Skin Temperature: fluctuates according to environmental  temperature.  Rectal Temperature represents core temperature.  Oral Temperature is 0.5°- 1° C lower than the rectal temperature.   Normal Oral Temperature : 37°C. In the morning may drop slightly: 36.7°C. Circadian Fluctuation is about 0.5 to 0.7°C. Mouth breathing, chewing gum, drinks,  Children : 0.5°C higher than adults.  Skin temperature of different parts of the body shows fluctuations. Extremities are cooler. Scrotum temperature is as low as 32°C.  Rectal temperature : as high as as 40°C due to exercise. Muscle contraction, including shivering, increases temperature.

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Physical State, Infection, Emotion, Epinephrine Hormonal (mainly Thyroid) disturbances: change body temperature. Temperature – raising mechanisms and Temperature –  lowering mechanisms respond to temperature receptors in order to maintain body temperature Endogenous Pyrogens (Cytokines produced by monocytes, macrophages and Kupffer cells) act on the Preoptic area of  the hypothalamus to increase prostaglandins synthesis. Prostaglandins of the hypothalamus raise the temperature set point (change the thermostat setting) leading to FEVER. Aspirin inhibits prostaglandins synthesis to relief fever.

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Practical: 1 – At rest : Record oral temperature (don’t chew gum or  drink fluid or mouth breath for at least five minutes) 2 – At rest : Record oral temperature : following mouth  breath; Hot drink; Cold drink (What about HOT PEPPER) 3 – Record oral temperature following exercise. 4 – Record skin temperature of the forehead, hands and feet at rest and at room temperature. 5 – Repeat step 4 – following exposure to cold and warm environment. 6 – Repeat step – 4 following exercise. 7 – Write a report on the recorded results.

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