thermoregulation Flashcards
what body systems/ processes can be affected by heat stress/ hyperthermia?
-Brain function
-digestive tract
-muscles
-metabolism
-cardiac
-respiratory
-Cardiovascular
What factors contribute to performance?
-strength
-flexibility
-power
-speed
-aerobic endurance
-anaerobic endurance
what is average core temperature for humans?
Between 35-42, average is 37
Why is there a set point for core temperature at 37c and what happens to blood flow in certain conditions in order to maintain core temp?
body functions are optimised at this temperature
-when cold-blood flow increases to core in order to maintain core temp
-when warm-bloow flow increases to skins surface
What are 3 methods to measure body temperature?
-Skin blood flow measurement (can see where blood flow is being redistributed)
-Sweat rate: by body mass loss(measure weight before and after exercise), sweat patches or capacitance hygrometry
-Core temperature measurement (by rectal measurement)
what is the chain of exercise command within the body?
Brain > spinal cord > peripheral nerves > muscle sarcolemma > Ca release > cross-bridge formation > power output
what has happened to the chain of exercise command if maximum power output is reached or if there’s a reduction of power output?
-if maximum power output is achieved then heat must have impacted one of the stages within the chain
- If there is a reduction of power output (usually in endurance exercise) there is a negative effect on one of the stages
what are the reasons for maximal power output being achieved/ limited?
-increased rate of phosphocreatine utilisation
-greater ATP turnover and adenine nucleotide degradation
-accelerated muscle fibre conduction velocity
-increased cross bridge cycling rate
How is core temperature maintained during anaerobic endurance exercise?
-Linear relationship between muscle temp and speed/strength/power (as one increases so does the other)
-Core temperature becomes elevated at some point during exercise
-Strength/power/speed overall continues to increase but at a slower more gradual rate than before
Why does core temp increase during exercise?
-Is maintained until point where environmental increases greatly so we can’t adjust any longer so core temperature starts to rise instead
what are methods of heat loss from the body?
-convection, conduction, radiation & evaporation
what are methods of heat gain to the body?
-posture, resting metabolic rate, thermic effect of food, physical activity, environment
how is body heat balance maintained?
-must be balance between heat loss and heat gain
formula for heat storage?
Heat storage = heat production ± heat loss (± Cv ± Cd ±R ±E)
what is radiation?
the emission of electromagnetic heat waves