2. THERMOREGULATION
▸BODY TEMPERTURE DEPENDS ON HEAT
PRODUCTION AND HEAT LOSS
▸HEAT PRODUCTION IS CALLED THERMOGENESIS
▸HEAT LOSS IS CALLED THERMOLYSIS
▸HEAT IS PRODUCED AS THE PRODUCT OF
METABOLISM AND LOST IN THE ENIVORNMENT
▸MAMMALS ARE HOMEOTHERMS
▸NORMAL CORE BODY TEMPERATURE IS 36-37.5’ C
3.
4. CORE BODY TEMPERATURE
THE CORE BODY
TEMPERATURE IS 37’C
IT INCLUDES ORGANS
LIKE HEAD,THORAX
AND ABDOMEN WHERE
THE VITAL ORGANS
ARE LOCATED
THEIR ENZYME SYSTEM
MUST OPERATE IN
OPTIMUM CONDITION
THE PERIPHERY OF
THE BODY CAN
WITHSTAND SOME
DEVIATION FROM THE
CORE TEMPERATURE
5. CONDUCTION CONVECTION RADIATION
Energy is transferred by
direct contact
Occurs in gasses and
liquids
Energy is transferred by
electromagnetic waves
(visible light, microwaves,
infrared )
Energy flows directly from
warmer to cooler objects
Movement of large number
of particles in same
direction
All objects radiates energy
Continues until object
temperature are equal
Cycle occurs while
temperature differences
exist
Can transfer energy
through empty space
8. nerves
More heat generated
Less water covers the skin.
Less evaporation
Skin arteries constrict
Less blood to the skin.
Less radiation &
conduction of heat
Muscles of
skin arteriole
walls constrict
Sweat
glands
decrease
secretion
Muscles
shivering
nerves
Core body
temperature
<37°C
Thermoreceptors
Hypothalamus
11. HYPOTHERMIA
▸PERIOPERATIVE HYPOTHERMIA IS BECAUSE THE
INHIBITION OF THERMOREGULATION INDUCED BY
ANAESTHESIA AND PATIENT EXPOSURE TO COLD
ENVIRONMENT
▸HYPOTHERMIA COMPLICATION:
SHIVERING
PRONLOGED DRUG EFFECT
COAGULOPATHY
SURGICAL WOUND INFECTION
MORBID CARDIAC EVENTS
12. TEXT
PROCESSING OF THERMOREGULATORY INFORMATION:
AFFERENT INPUT
CENTRAL CONTROL
EFFERENT RESPONSE
A. GENERAL ANESTHESIA AFFECTS ALL 3 ELEMENTS.
B. REGIONAL ANESTHESIA AFFECTS AFFERENT &
EFFERENT COMPONENTS
PERIOPERATIVE TEMPERATURE
CHANGES
13. ‣ RESETTING OF THE HYPOTHALAMIC THERMOSTAT
EVENTS THAT CONTRIBUTE TO DECREASES IN
BODY TEMPERATURE DURING SSURSUSURGERY
