Lecture 13 - Temperature Regulation

Question 1

Area in the brain is responsible for temperature regulation??

RL13 S48

Answer 1

Anterior preoptic hypothalamic nuclei of hypothalamus.

Question 2

What are warm sensitive neurons and what is the effect of their stimulation?

RL13 S49

Answer 2

Contains temperature set point.

Activates paraventricular nucleus and lateral hypothalamus.
-results in parasympathetic activation and heat dissipation

Question 3

What are cold sensitive neurons and what is the effect of their stimulation?

RL13 S50

Answer 3

Activates posterior hypothalamus:

-result in sympathetic activation and heat conservation/generation

Question 4

What are the mechanism of body heat reduction?

RL13 S51

Answer 4

• vasodilation
• sweating
• decrease in heat production

Question 5

What are the mechanisms of increasing body heat?
Which is the most common and which is the most potent?

RL13 S51

Answer 5

• vasoconstriction
• piloerecetion
• shivering (most potent)
• increase in basal metabolic rate (most common)
• thyroxin secretion
• norepinephrine

Question 6

What are causative factor of fevers and what effect does IL-1, prostaglandins, and aspirin have on fever?

RL13 S54

Answer 6

Causes:

• brain abnormalities
• surgery around hypothalamus
• prostaglandins
• lipopolysaccaride toxins

IL-1 and prostaglandins:
-increase temperature set point

Aspirin:
-decrease temperature set point (inhibition of cycloocygenase and prostaglandins)