1. Temperature Regulation EQ How does our body regulate temperature?

2. 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

4. Respiration
Heat loss as the result respiratory vapor is exhaled

5. Radiation
Thermal radiation is energy transfer by the emission of electromagnetic waves which carry energy away from the emitting object.

6. Evaporation
Water on and in your skin turn to vapor

7. Convection
Heat loss as the result of the movement of air or water surrounding

8. Conduction
Heat loss as the result of direct contact with the skin

9. Role of Skin

10. Heat Exchange in the Skin

11. Vasoconstriction and Vasodilatation

12. Thermoregulation
Temperature is regulated by nervous feedback mechanisms
Thermoregulatory center located in the Hypothalamus
Thermoregulatory regulatory responses include
Autonomic
Somatic
Endocrine
Behavioural changes

13. 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

14. Body Temperature Control System
Hypothalamus
Acts as a thermostat
Receives nerve impulses from cutaneous thermoreceptors
Hypothalamus- also has thermoreceptors called central thermoreceptors
These detect changes in blood temperature

16. Thermoregulatory regulatory responses
Activated by Exposure to Cold
Shivering
Increase voluntary activity
Increase TSH secretion
Increase Catecholamines
Vasoconstriction
Horripilation
Curling up

17. Thermoregulatory regulatory responses
Activated by Exposure to Heat
Vasodilatation
Sweating
Increase in Respiration
Anorexia
Apathy
Decrease TSH secretion

18. 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

19. Hypothermia –Body temp below the normal lower limit (<970F)
Contd----
Hypothermia –Body temp below the normal lower limit (<970F)
Thermoregulatory responses
Greatly impaired at (<940F)
Lost at body temp(<850F)

20. Contd---- Frostbite Occurs at very low temp Common sites-
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

21. Summary of Effector Mechanisms in Temperature Regulation

22. Left Side Activity
Copy the mechanisms of heat loss (slide 3) and Summary of Effector Mechanisms in Temperature Regulation (slide 21) into your notebook