ANS and Hypothalamus

Question 1

Where is hypothalamus?

Answer 1

Basal region of diencephalon, part of lateral wall of III ventricle

Question 2

What are the main functions of the hypothalamus?

Answer 2

Homeostasis- maintain constant internal environment
- bp, body temp, food intake, bg, metabolic rate, water balance, hr
Rheostasis
growth
repro development and function

Question 3

How is thermoregulation achieved?

Answer 3

Too hot: ant hyp neurones promote peripheral vasodilation and sweating
Too cold: post hyp- peripheral vasoconstriction, shivering, piloerection, brown fat thermogenesis

Question 4

What are the effects of leptin?

Answer 4

Decreased appetite
Increased metabolic rate
Increased reproduction

Question 5

Describe the orixogenic and anorectic neurones in the mediobasal hypothalamus?

Answer 5

Leptin acts at arcuate nucleus

Question 6

Define rheostasis and give two examples

Answer 6

Changes in internal environment which anticipate external changes

• circadian rhythm/seasonal variation
• internal body clock- 24.5 hours

Question 7

Why do we have endogenous clocks?

Answer 7

To anticipate changes in external environment