Although not as immediately critical as the availability of oxygen and glucose, it is important for the nervous system of ectothermic humans to maintain normothermia for effective cellular functioning (Morrison, 2011). The principle source of heat originates from the body. Temperature control mechanisms in humans consist of both core and peripheral processes. Responses elicited occur in a feed-forward manner. Changes in thermoreceptors in primary sensory nerve endings distributed to the skin are transmitted to the pre-optic area, a sensori-motor integration site, rostral to the hypothalamus. These effector pathways are regulated and integrated for thermoregulation (Morrison, 2011). Cutaneous blood vessels, brown fat (unknown significance in
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Two anatomically distinct afferent signals, warm-sensitive and cold-sensitive neurons are processed within the pre-optic area (Buggy & Crossley, 2000). Warm-sensitive and cold-sensitive neurons increase activity with increased brain temperature, and decreased temperatures in the skin and in oral and urogenital mucosa, respectively (Romanovsky, 2007). Warm-sensitive neurons increase firing rates with warming and decrease with cooling. Cold sensitive neurons increase firing rate with increased cooling or decreased warming (Boulant & Dean, 1986). These responses are triggered by large thermal exposures that affect heat exchange between the body and the environment (Romanovsky, …show more content…
When exposed to opposing or conflicting information, the different combinations of changes detected are expected to trigger different autonomic responses (Romanovsky, 2007). A study explored the different effects of warming on body heat and core temperature on anaesthetised cooled humans (≈34˚C) suggested that cutaneous warming systems depended upon “skin temperature, tissue insulation, and circulatory convection of heat”. Upon forced warming, heat transferred to the periphery (extremeties) and core warming was “substantially delayed” (Taguchi, Ratnaraj, Kabon Sharma, Lenhardt, Sessler, Kurz, 2004). Surface warming counters the feedback loop from skin temperature to hypothalamic thermoregulation centres. The greater the proportion of surface area warmed by external forces, the greater the effect on mean skin temperature and core temperature (Badjatia, Strongilis, Prescutti, Fernandez, Fernandez, Buitrago, Schmidt, Mayar,
Two anatomically distinct afferent signals, warm-sensitive and cold-sensitive neurons are processed within the pre-optic area (Buggy & Crossley, 2000). Warm-sensitive and cold-sensitive neurons increase activity with increased brain temperature, and decreased temperatures in the skin and in oral and urogenital mucosa, respectively (Romanovsky, 2007). Warm-sensitive neurons increase firing rates with warming and decrease with cooling. Cold sensitive neurons increase firing rate with increased cooling or decreased warming (Boulant & Dean, 1986). These responses are triggered by large thermal exposures that affect heat exchange between the body and the environment (Romanovsky, …show more content…
When exposed to opposing or conflicting information, the different combinations of changes detected are expected to trigger different autonomic responses (Romanovsky, 2007). A study explored the different effects of warming on body heat and core temperature on anaesthetised cooled humans (≈34˚C) suggested that cutaneous warming systems depended upon “skin temperature, tissue insulation, and circulatory convection of heat”. Upon forced warming, heat transferred to the periphery (extremeties) and core warming was “substantially delayed” (Taguchi, Ratnaraj, Kabon Sharma, Lenhardt, Sessler, Kurz, 2004). Surface warming counters the feedback loop from skin temperature to hypothalamic thermoregulation centres. The greater the proportion of surface area warmed by external forces, the greater the effect on mean skin temperature and core temperature (Badjatia, Strongilis, Prescutti, Fernandez, Fernandez, Buitrago, Schmidt, Mayar,