Body Temperature Regulation Flashcards
Why is it important for core temperature to be regulated?
Cannot survive if not functioning
What influences the rate of hear production?
Basal rate metabolism
Metabolism inc by muscular activity
Metabolism inc by sympathetic stimulation
Metabolism inc by hormonal effect on cells
Metabolism inc by inc chemical production
Inc digestion, absorption and storage of food
Where is most heat lost?
Through the skin
What are some barriers to heat transfer?
Insulation
Skin
SubQ tissue
Fat - conducts 1/3 more heat than other tissues
Where are the temperature regulating centers?
Preoptic and anterior hypothalamic nuclei
What is the main mediator of fever when there is an infection?
Pyrogenic
What regulates homeostatic mechanisms to maintain a body temp set point?
Hypothalamus
What ate the mechanism to increase body temp?
Vasconstriction
Thermogenesis
Piloerection
What is vasoconstriction?
Tightening of vasculature in the skin
What is vasoconstriction mediated by?
Tonic sympathetic control - noradrenergic
Nonglabrous (hairy) glabrous (palm, soles), skin all have sympathetic inn
What is thermogenesis?
Shivering to inc heat production
Chemical by sympathetic stimulation and thyroxin
What are the chemical thermogenesis agents?
Norepinephrine and epinephrine
How is thermogenesis stimulated?
By the uncoupling oxidative phosphorylation in mitochondria so heat, not ATP, is released
Where does the most uncoupling oxidative phosphorylation occur?
In brown fat
What does thyroxin do as a chemical thermogenesis?
Increases the rate of cellular metabolism