Chapter 9 Flashcards
What do birds generate that prepare them for seasonal change?
Endogenous circannual rhythm
endogenous means generated from within
What is endogenous circadian rhythm?
last about a day
What does the body have for wakefulness and sleep?
Rhythm
How does the circadian rhythm differ among individuals?
“morning ppl” awaken early & quickly become productive & less as the day progresses
“evening ppl” warm up more slowly both literally & figuratively reaching their peak late in the afternoon
Do ppl older than 20 learn to go to bed earlier because they have jobs that require them to get up early?
1) how shifts continues gradually over decades
2) ppl were simply adjusting to their jobs
What is critical for resetting rhythms?
light
Free running rhythm is?
Rhythm that occurs when no stimuli reset or alter it
What stimulus resets the circadian rhythm?
Zetigeber
What happens in blind people trying to reset circadian rhythm?
Some set their circadian rhythm by noise, temperature, and meal activity
What happens to the circadian rhythm when going from east to west?
Phase delay- stay awake later at night & awaken late in morning easier
What happens to the circadian rhythm when going from west to east?
Phase advance- sleep earlier and awaken earlier harder
What are the effects of cortisol?
damage neurons in the hippocampus a brain area important for memory.
What is the part of the hypothalamus provides the main control of the circadian rhythms for sleep and body temperature?
Suprachiasmatic nucleus
What does melatonin do?
regulates waking and sleeping by controlling activity levels in other areas of the brain
