Thermoregulation Flashcards
What is body temperature
Heat produces- heat loss= body temperature
what methods are used to measure core temp
rectal, tempanic
what methods are used to measure surface temp
oral/ sublingual (armpit)
The process of maintaining balance between body heat produced and body heat gained is called what
thermoregulation
state factors that cause heat production
primary source: metabolism- by product of metabolic activity
Hormones
Muscle movement
Dietary induced
Main ways of heat loss
Primary: SKIN
urinations and faeces excretion
humidifying air within lungs/ expiring
Negative feedback loop
reversal of the issue
what are the responses of body temperature
behavioral or physiological
What maintains the constant range of body temperature
and describe the process
RECEPTOR: cold and hot receptors send input to control centre
thermoregulatory centre in the hypothalamus (CONTROL CENTRE) sends output to the effector
Effectors either produce or lose heat
(sends repose to receptors)
state the equation for thermoregulation
heat gain= heat loss
what are the 4 main ways for thermoregulation
conduction
radiation
evaporation
Convection
Describe conduction
diffusion process where molecules transmit their kinetic energy to other molecules by colliding with them
heat energy is transferred
Describe convection
Hot air flows to a cold material, it will heat that region.
Describe Radiation
Object will emit electromagnetic heat waves (no molecular contact)
eg: when temp of item exceeds temp of skin, radient heat energy is absorbed.
state the Physiological processes in heat reduction
vasodilation
metabolic rate decrease
sweat
Describe vasodilation
increase temp causes vasodilation of the blood vessels
results in Increase blood flow to the skin
Metabolic rate
changes with reduction in secretion of thyroxine
=decreased metabollic rate/ decreased heat produced
Sweat
Sweat= evaporation on the skin results in cooling
for sweat to be effective environmental temp must be lower than body tempreature
Vasoconstriction
Sympathetic nervous system
blood vessels vasoconstrict= lessbllod flow to the skin surface. blood flow is retained close to the body organs
HEAT IS NOT LOST TO THE BODYS SURFACE
Muscle contraction
Hypothalamus= increase muscle tone= increased body heat production
Rhythmic muscle tremors
piloerection- layer of warm still air is trapped next to skin
Hypothalamus and adrenal medullas role with production of heat
hypothalamus stimulated adrenal medulla via the sympathetic nerves
adrenal medulla secretes nor adrenaline and adrenaline results in increase cellular metabolism and increase heat production
which organ releases thyroxine
thyroid
describe hypothalamus relationship with the anterior pituitary gland
hypothalamus stimulates anterior pitatry gland
anterior pituatry gland releases thyroid stimulating hormone- stimulated thyroid to release thyroxine
results in increase metabolic activity
what does the adrenal medulla secrete
noradrenaline and adrenaline
What are the 3 phases of a fever
chill phase
plateau phase
defervescence phase
Describe the chill phase of a fever
heat production responses due to a high hypothalamic temp set point
Describe plateau phase of a fever
core temp reaches new set point
Describe Defervescense (breaking) phase
heat loss mechanism as the hypothalamic set point has been readjusted to normal body temp
