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Temperature Regulation EQ How does our body regulate temperature?. Body Temperature. Normal Body Temperature (NBT) – 98.6 0 F(37 0 C) Rectal Temp ----- (0.5 0 F to 1 0 F) above the Oral Rectal Temp reflects the internal body Temp (Core Body Temp)
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Temperature RegulationEQ How does our body regulate temperature?
Body Temperature • Normal Body Temperature (NBT) – 98.60F(370C) • Rectal Temp ----- (0.50F to 10F) above the Oral • Rectal Temp reflects the internal body Temp (Core Body Temp) • Core Body Temp remain almost constant • Skin Temp (Shell Temp)-----Variable
Respiration • Heat loss as the result respiratory vapor is exhaled
Radiation • Thermal radiation is energy transfer by the emission of electromagnetic waves which carry energy away from the emitting object.
Evaporation • Water on and in your skin turn to vapor
Convection • Heat loss as the result of the movement of air or water surrounding
Conduction • Heat loss as the result of direct contact with the skin
Thermoregulation • Temperature is regulated by nervous feedback mechanisms • Thermoregulatory center located in the Hypothalamus • Thermoregulatory regulatory responses include Autonomic Somatic Endocrine Behavioural changes
Feedback system • 1) Receptor • Sensor that responds to changes (stimuli) • 2) Control Center • Sets range of values • Evaluates input and • Sends output • 3) Effector- • Receives output from control center • Produces a response
Hypothalamus Acts as a thermostat Receives nerve impulses from cutaneous thermoreceptors Hypothalamus- also has thermoreceptors called central thermoreceptors These detect changes in blood temperature Body Temperature Control System
Thermoregulatory regulatory responses Activated by Exposure to Cold Shivering Increase voluntary activity Increase TSH secretion Increase Catecholamines Vasoconstriction Horripilation Curling up
Thermoregulatory regulatory responses Activated by Exposure to Heat Vasodilatation Sweating Increase in Respiration Anorexia Apathy Decrease TSH secretion
Thermoregulatory regulatory responses Exposure to Cold Shivering Increase voluntary activity Increase TSH secretion Vasoconstriction Horripilation (erection of hairs) Curling up Exposure to Heat Vasodilatation Sweating Increase in Respiration Apathy Decrease TSH secretion
Contd---- • Hypothermia–Body temp below the normal lower limit (<970F) • Thermoregulatory responses Greatly impaired at (<940F) Lost at body temp(<850F)
Contd---- • Frostbite Occurs at very low temp Surface area freezes Ice crystals formed • Common sites- Lobes of the ears Digits of hands Digits of feet • Cold induced vasodilatation- Final protection against frostbite
Left Side Activity • Copy the mechanisms of heat loss (slide 3) and Summary of Effector Mechanisms in Temperature Regulation (slide 21) into your notebook