Ch. 9.1. Temperature regulation Flashcards
How does the idea of allostasis differ from homeostasis?
Homeostasis keeps certain body variables within a fixed range by reacting to changes.
Allostasis acts in advance to prevent or minimize changes.
What is the primary advantage of maintaining a constant high body temperature?
A constant high body temperature keeps an animal ready for rapid, prolonged muscle activity even in cold weather.
Why did mammals evolve a temperature of 378C (988F) instead of some other temperature?
Animals gain an advantage in being as warm as possible and therefore as fast as possible. However, proteins lose stability at temperatures much above 378C (988F).
What are the sources of input to the POA/AH?
(pre-optic-area/anterior-hypotalamus).
The POA/AH receives input from temperatures in the skin, the organs, and the hypothalamus. It also receives prostaglandins and histamines when the immune system detects an infection
If you had damage to your POA/AH, what would happen to
your body temperature?
You would be much less able to shiver, sweat, or control other physiological mechanisms that control body temperature. However, you could still try to find a place in the environment that keeps you close to your normal temperature.
What evidence indicates that fever is an adaptation to fight
illness?
The body will shiver or sweat to maintain its elevated temperature at a nearly constant level. Also, fish, reptiles, and immature mammals with infections use behavioral means to raise their temperature to
a feverish level. Furthermore, a moderate fever inhib- its bacterial growth and increases the probability of surviving a bacterial infection.
What is meant by allostasis?
Processes that anticipate future needs
Well over half of the human body’s energy is devoted to ____ _______
basal metabolism
What is the primary advantage of maintaining a constant high body temperature?
keeps the muscles ready for long an rapid movement even in cold weather
If we inserted a probe into your POA/AH and heated it, what would happen?
You would sweat.
When you have an infection, what causes the fever?
The immune system delivers prostaglandins and his- tamine to the hypothalamus.
