Exam 4: hot/cold temps

What is the regulation of body temperature around a physiological set point?

Thermoregulation

humans are considered what due to internal body temperature regulated at a nearly constant temp despite external factors?

homeothermic

what is the normal internal temperature range for humans in celcius?

36.1-37.8

Metabolic Heat production occurs from ATP breakdown into what?

cellular work, metabolic heat

What is the heat transfer from one solid material to another through direct molecular contact such as a heat pack?

conduction

what is the heat transfer by movement of gas or liquid across a surfacesuch as air passed over skin?

convection

what is the transfer of heat in the form of infrared rays?

radiation

what is the resistance to dry heat?

insulation

when air and skin temperature are similar what is the only way for the body to cool itself?

evaporation

what is the heat loss via phase change from liquid to gas off of the skin?

evaporation

What is the body’s thermoreceptors in the brain that receives input from sensory thermoreceptors?

preoptic anterior hypothalamus

A core temperature greater than what in C will inhibit physiological function?

40

what receptor is very sensitive to the rate of change and chemical change as little as 0.01 degree?

central thermoreceptor

Impaired performance of the cardiovascular system increases the chances of what due to the heart not pumping enough blood to active tissue?

overheating

The brain begins to shut down and roughly what internal temperature in C?

40

What health risk of is the least serious of heat related illness that is triggered by sodium loss and dehydration causing severe, painful cramping?

heat cramps

What heat illness is caused by severe dehydration from sweating that results in fatigue, nausea, weak/rapid pulse and dizziness?

heat exhaustion

What is the life threatening heat illness resulting from thermoregulatory mechanism failure characterized by disorientation and a core temp of >40 degrees C?

heat stroke

what is the short term (days/weeks) adaptation to environmental stressors?

acclimation

What is the long term (months/years) adaptation to environmental stressors?

acclimatization

What occurs in any environmental condition causing the loss of body heat?

cold stress

what occurs after repeated cold exposures without significant heat loss where vasoconstriction and shivering are blunted?

cold habituation

what occurs after repeated cold exposures with heat loss and enhanced metabolic/shivering heat production?

metabolic acclimation

what occurs when increased metabolism cannot prevent heat loss enhancing skin vasoconstriction and increased skin vasoconstriction?

insulative acclimation

what occurs form excessive vasoconstriction leading to lack of O2 and nutrients then eventually tissue death as a result of prolonged exposure to cold?

frostbite

what affects up to 50% of winter sport athletes who experience excessive airway drying?

exercise induced asthma

At what temperature in celcius is thermoregulation completely lost when exercising in cold weather?

29.5

At what core temperature does thermoregulatory function become comprised in C?

34.5