Year: 2009
Type: article
Abstract: Humans have extensive abilities to adjust their thermoregulatory activities when responding to changes in both endogenous (exercise) and exogenous (environmental) conditions and thereby maintain thermal homeostasis.Five phenotypic adaptations may be described: reduced heart rate at a fixed work rate; expanded plasma volume; lower core temperature at an equivalent workload; superior sodium and chloride reabsorption from sweat; and an elevated sweat secretion.Thermal factors such as core and skin temperatures are the primary afferent signals that modulate sweat rate and skin blood flow.However, it is also suggested that various non-thermal factors associated with exercise (central command, muscle mechano-and metabo-reflexes, and baroreflexes) can modify sweat rate and skin blood flow.Thermoregulatory controls of sweating and cutaneous vasodilation during heat stress are also modified by circadian changes in core temperature, as well as secretion of endogenous melatonin.Moreover, high humidity reduces sweat efficiency, and therefore core temperature increases during exercise when humidity is elevated at a fixed temperature.In this case, the ability to maintain dry heat loss at the expense of a reduced capacity of evaporative heat loss is seen as an important contributing factor to thermoregulation in humid environments.
Institution: Kobe University
Language: English
Subfield: Physiology (medical)
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2168433335