The document discusses body temperature regulation and abnormalities. It defines normal body temperature ranges and explains how the hypothalamus regulates temperature through heat gain and loss mechanisms. When body temperature varies by 0.1°C from the 37°C set point, the hypothalamus activates mechanisms like sweating or shivering. Abnormalities include hypothermia, hyperthermia, and heat stroke. Fever is an regulated increase in set point to fight infection through pyrogens like interleukin-1. Frostbite can occur if extremities are exposed to freezing temperatures.

1. BODY TEMPERATURE
AND ITS REGULATION
Dr Nisar Ahmed Arain
Assistant Professor
Anesthesia/Critical care/ER

2. SLOS
-1-Introduction
-2-Normal Temperature
-3-Heat Loss Mechanism
-4-Heat Gain Mechanism
-5-Regulation of body Temperature
-6-Abnormalities of body Temperature
regulation

3. INTRODUCTION
-Homeo-thermic-Maintaining constant
internal body Temperature
-Endotherms -Generate their
own body Heat
Why Temperature should be
maintained
-1-For normal enzyme activity
-2-For normal neuronal activity
-3-Rise in high Temperature.
cause denature of proteins

4. BOY TEMPERATURE
-BODY TEMPERATURE
Core Temperature measured in
-Oral or
-Rectal routes
-VALUES of Normal body Temperature
-1-Oral : 98.6-degree F (97.3 – 98.8-degree F
OR
37 degree C(36.3 – 37.1 degree C)
-2-Rectal :0.5 degree C more then Oral
-3-Axilla :0.5 degree C less than Oral
-4-Skin :Depends upon environment
-5-101 degree to 104-degree F
RECTAL 0.5 degree C > ORAL 0.5 degree C >0.5 degree C > AXILLA

5. BOY TEMPERATURE

6. MAINTAINANCE OF
BODY TEMPERATURE
Heat Loss Heat Gain
=

7. HEAT GAIN MECHANISM
-1-Shivering
-2-Increase in metabolism by Epinephrine
nor-epinephrine and Thyroxin
-3-Cutaneous vasoconstriction

8. HEAT LOSS MECHANISM
-1-Evaporation of sweat
-2-Radiation
-3-Conduction and Convection
-4-Cutaneous vasodilation
-5-Decrease in Metabolism
-6-Through Respiration

9. -Receptors: Warmth and Cold receptors from skin, Deep tissues
spinal cord and Hypothalamus
-Heat loss center – Pre-optic and Anterior Hypothalamic Nuclei
-Heat Gain Center – posterior hypothalamus
-Set point 37 degree C in Hypothalamus
(+-) 0.1 degree C cause Hypothalamus to activate heat loss
or heat gain mechanism
Regulation of body temperature
Role of the Hypothalamus

10. Preoptic & Ant.
Hypothalamic
nuclei
Posterior
hypothalamus
Inhibition of
Sympathetic
nervous system
-Vasodilation
Sweating
decrease in thermogenesis
(heat production).
-Increase in
body
temperature
- Warmth receptors from
skin
deep viscera are stimulated
TEMPERATURE-DECREASING MECHANISMS
when the body is too HOT
Normal body
temperature set

11. Posterior
Hypothalamus
Sympathetic
stimulation
-Skin vasoconstriction throughout
the body piloerection
-Increase in Thermogenesis
(Heat Production)
-Normal body
temperature
Set point: 37D C
Decrease in body
Temperature
Cold receptors from
Skin are stimulated
-Pre-optic and Anterior
Hypothalamic Nuclei
Temperature-increasing mechanisms when the body too COLD

12. RESPONSE OF HYPOTHALAMUS

13. ABNORMALITIES OF BODY TEMPERATURE REGULATION
-HYPOTHERMIA :-Decrease in body temperature below normal range
-HYPERTHERMIA:- Increase in boy temperature above normal range
-HYPERTHERMIA - FEVER
-1-Increase n body Temperature above Normal
-2-Due to rise in set point of Hypothalamus
by pyrogen
-3-Pyrogen:-Any substance that raises the
“set point” of Hypothalamus
a-Bacterial endotoxins:-Cell membrane
proteins and their breakdown products
b-IL-1
C-Inflamatory mediators;-Kinin, Brady
-Kinin, Prostaglandin E
-4-Characteristics of febrile condition
a-Crisis
b-Fever
c-Crisis or Flush
-5-Anti-Pyretics:-Aspirin blocks PG-E

14. HEAT-STROKE
-This occurs when body temperature rises beyond the
“critical temperature”. It ranges from 105 to 1080F
SYMPTOMS
-1-Dizziness
-2-Abnormal distress
-3-Vomiting
-4-Delirium
-5-Loss of consciousness
-6-Circulatory shock
-7-Death

15. TEPIDS SPONGING

16. HYPOTHERMIA
-If person is exposed to “Iced water” for 20 to 30 minutes
ordinarily dies because of Heart Fibrillation
-If the body Temperature has fallen below 85°F,the
abilityoftheHypothalamus toregulateTemperature islost
FROST BITE
-When the body is exposed to extremely
low temperatures surface areas can freeze
this freezing is called “Frost-bite”
-This occurs specially in the
a-Lobes of the ears and in the
b-Digits of the Hands and Feet