temperature regulation


regulation

 [reg″u-la´shun] 1. the act of adjusting or state of being adjusted to a certain standard.2. in biology, the adaptation of form or behavior of an organism to changed conditions.3. the power to form a whole embryo from stages before the gastrula.4. the biochemical mechanisms that control the expression of genes.hemodynamic regulation in the nursing interventions classification, a intervention" >nursing intervention defined as optimization of heart rate, preload, afterload and contractility. See also hemodynamic monitoring.temperature regulation in the nursing interventions classification, a intervention" >nursing intervention defined as attaining and/or maintaining temperature" >body temperature within a normal range.temperature regulation: intraoperative in the nursing interventions classification, a intervention" >nursing intervention defined as attaining and/or maintaining desired intraoperative temperature" >body temperature.

temperature regulation

The process by which body temperature is maintained within narrow limits. Blood temperature is monitored in the hypothalamus of the brain. A drop in temperature prompts closure of the skin blood vessels and shivering; a rise in temperature results in skin flushing and sweating so that heat may be lost by radiation and evaporation. In fevers, the hypothalamic thermostat is set high and shivering and skin vessel closure raise the temperature.

temperature regulation

the maintenance of body temperature at a steady level. This occurs to some extent in all vertebrates and many invertebrates, but applies particularly to HOMOIOTHERMS. In humans, a constantbody temperature of 36.9 °C is maintained, and this is the optimum temperature for normal metabolic reactions involving enzymes.

Various mechanisms bring about temperature regulation. In mammals and birds, hair and feathers trap air which acts as insulation. Sweating acts as a cooling mechanism, and animals in cooler climates have a smaller surface area/volume ratio (see BERGMANN'S RULE). Subcutaneous fat also acts as an insulation; superficial blood vessels constrict in response to cold and dilate in warm conditions, so taking blood away from the skin surface when it is cold and to the skin surface when warm. The centre for controlling body temperature lies in the HYPOTHALAMUS.

Plants also control their temperature and keep cool by transpiration, losing the latent heat of EVAPORATION. On the loss of too much water they wilt, but this results in their leaves being moved (by drooping) from the direct rays of the sun so that in effect they remain cooled until sunset.