Thermoregulation Flashcards
What is the normal temp of the body?
-37 (98.6)
What happens with increased temperature to the body?
- blood vessels dilate, giving flushed apperance
- sweat glands become more active
What happens with decreased temperature in the body?
- blood vessels constrict, heat is trapped in deeper tissues
- sweat glands become less active
- skeletal muscles contract, causing shivering
What is thermoregulation?
Process of maintaining the core body temperature at nearly constant value (balance heat loss and gain)
What is hypothermia?
-temp below normal range (<36.2)
What is hyperthermia?
Temp above normal range (>37.6)
What is hyperpyrexia?
-extremely high body temp (41.5)
What is fever?
-immune system response to pyrogens that trigger the hypothalamus in the brain to adjust heat production, heat conservation, heat loss mechanisms to maintain higher core temp, increased hypothalamic set point
What are exogenous pyrogens?
-external origin, bacterial endotoxins, viruses, antigen antibody complex
What are endogenous pyrogens?
-produced by phagocytic white blood cells as par to fate immune responses and include IL-1, TN, interferon
What is normothermia?
State in which body temp is in normal range
What is conduction?
-heat transferred by direct contact
What is evaporation?
Sweating
What is radiation?
-electromagnetic waves that emit heat from skin surfaces to the air
What is vasodilation for?
Heat loss
Who are at risk for hyperthermia?
-cardiovascular disease, diabetes, peripheral vascular disease (taking certain meds)
What are mechanisms that can lead to hyperthermia?
-excessive heat production, inadequate ability to cool, or hypothalamus regulator dysfunction
What are consequences for hyperthermia?
- cardiovascular disease, damage to nervous system
- excessive sweating paired with high body temp=sodium loss, dehydration
- lead to hypotension, tachycardia, decrease CO, reduced perfusion, coagulation
What can lead to cerebral Edema, CNS degeneration and renal necrosis?
-high core temp, and reduced perfusion
What are hyperthermia risk and prevention tips?
Keep out of sun, house cool, use shade, sunny=close blinds, open second story windows
- drink water, take cool shower, limit physical activity
- maintain the envrinment temp (24)
- replace electrolytes, salts, minerals
What two ways can hypothermia be?
-accidental or therapeutic
What is level of mild, moderate, severe hypothermia?
- 34-36 (93-96)
- 30-34 (86-93)
- <30 or <86
What are physiological factors for hypothermia?
-excessive heat loss, insufficient production of heat, or dysfunction of hypothalamic regulatory mechanism
What are some consequences of hypothermia?
- vasoconstriction (peripheral tissue ischemia)
- body temp decrease
- reduced perfusion
