Temperature homeostasis Flashcards
What does it mean that humans are homeothermic?
They are warm-blooded.
Why does the body temperature need to be maintained within narrow limits?
It is essential for the maintenance of normal bodily processes.
What is the normal human average body temperature?
36.7+/- 0.5 degrees celsius.
What can alter the measured human body temperature?
Sampling site, age, gender and time of day e.g. oral, rectal or tympanic.
Why does the body temperature increase during the second half of the menstrual cycle?
The effects of progesterone.
What are sources of heat input?
Internal production and external input such as metabolism and muscle contraction and from the environment via radiation or conduction.
What are some sources of heat losses to the environment?
Radiation, conduction, convection and evaporation.
What accounts for heat losses in the body?
20-30% is from sweating and respiration and 70% is from radiation.
What is the thermoneutral zone?
The range of ambient temperature over which the heat from the basal metabolism is sufficient to maintain the body core.
What is the ambient temperature?
The environmental temperature.
What is the main physiological thermoregulatory challenge?
Low temperature.
What temperature can naked humans thermoregulate at?
Between 10-55 degrees celsius.
Where is the thermoregulatory centre?
In the hypothalamus.
What does the hypothalamus do?
It integrates sensory input from thermoreceptors located in the core and periphery (skin).
Where is an increase blood temperature detected?
The anterior hypothalamus.
