Lesson 13 - Exogenous Zeitgebers

Question 1

What are exogenous zeitgebers

Answer 1

External cues

Question 2

What is the most important exogenous zeitgeber

Answer 2

Light

Question 3

How does light effect the SCN

Answer 3

• Receptors in SCN are sensitive to changes in light

• Use this info to synchronise activity of body’s organs/glands

Question 4

What is melanopsin

Answer 4

Protein in retina
-very sensitive to natural light

Question 5

When do EPs and EZs conflict

Answer 5

• When people move to night shift/diff timezone

• EPs will try to impose but EZ will by out of sync

• Disrupted sleep, anxiety, decreased alertness/vigilance happens
-aka jetlag

Question 6

+ Blind people and circadian rhythms

Answer 6

• Blind people WITH light perception have normal circadian rhythms

• Blind people WITHOUT light perception DONT

• Supports EZ maintains EP

Question 7

(-) Studies in the Arctic

Answer 7

• Sun doesn’t set in summer

• Still have normal sleep patterns

• Sometimes EZ doesn’t effect EP