Exercise in the Heat Flashcards
core body temperature
the normal temperature of the human body at rest is 37
thermoregulation
the process that allows the body to maintain its core temperature
hypothalamus
region of the brain responsible for controlling body temperature
thermoreceptors
sensory receptors that detect changes in core body temp, sends info to the hypothalamus
heat acclimatisation
the process in which the body adjusts gradually to a change in environmental temperature
what defense mechanisms does the hypothalamus activate
evaporative and non-evaporative
cardiovascular drift
a decrease in stroke volume caused by an increase in heart rate
effect of heat on the respiratory system
- increased f
- increased risk of asthma symptoms
- overall decreased efficiency of the CV and respiratory system
evaporative techniques
- hypothalamus stimulates sweat glands
- increased sweat production
- sweat evaporates to cool
effects of evaporative techniques on CV
- decreased volume of blood plasma
- HR increases to maintain O2 delivery
- leads to CV drift
non-evaporative techniques
- increased Vol of blood to the skin
- blood redistributed to skin from muscles and organs
- vasodilation of arterioles and pre-cap sphincters at skin surface
effects of non-evaporative techniques on CV
- blood pooling at skin
- decreased VR and SV
- less blood delivering O2
- HR increases to maintain Q + O2 delivery
- leads to CV drift
heat tolerance improves after a few days and causes:
- a decrease in core body temp
- an increase in blood plasma volume
- a decrease in heart rate
full heat acclimatisation
- occurs in 2 weeks
- increased sweat rate
- increase evaporative techniques without electrolyte loss
