chapter 13 - sleep

Question 1

biorhythm

Answer 1

timing mechanism that controls biological processes
- linked to cycle of days and seasons produced by Earth’s rotation around sun

Question 2

circadian rhythm

Answer 2

daily rhythm of daylight activity and nocturnal sleep that dominates human behaviour

Question 3

endogenous:

Answer 3

control comes from within

Question 4

biological clock:

Answer 4

neural system that times behaviour by synchronizing it to the temporal passage of the real day
*animals can anticipate events

Question 5

what does the biological clock regulate (4)?

Answer 5

• feeding times
• sleeping times
• metabolic expression
• gene expression

Question 6

period:

Answer 6

time required to complete a cycle of activity

Question 7

circannual rhythm

Answer 7

yearly

Question 8

infradian rhythm

Answer 8

less than a year

Question 9

ultradian rhythm

Answer 9

less than a day

Question 10

free-running rhythms:

Answer 10

rhythm of body in absence of all external cues
- periods of 25-27 hours

Question 11

w/ free-running rhythms, how much does the sleep cycle shift each day?

Answer 11

about an hour

Question 12

how long are nocturnal free-running rhythms in constant dark? light?

Answer 12

constant darkness = shorter than 24 hours
constant light = longer than 24 hours

Question 13

how long are diurnal free-running rhythms in constant dark? light?

Answer 13

constant darkness = longer than 24 hours
constant light = shorter than 24 hours

Question 14

zeitgeber:

Answer 14

time setter - environmental event that determines/ maintain period of biorhythms

Question 15

what does an “entrained” biological clock allow us to do?

Answer 15

synchronize daily activities across seasonal changes

Question 16

2 things that disrupt our biorhythms:

Answer 16

• light pollution
• jet lag

Question 17

what role does the SCN plat in circadian rhythms?

Answer 17

main pacemaker
*above optic chiasm

Question 18

5 pieces of evidence for SCN’s role:

Answer 18

1. if damaged, daily activities lack normal organization
2. SCN cells increase metabolic activity during light period
3. cells are more electrically active during light period
4. SCN neurons maintain rhythmic activity in absence of in/output
5. cells in a dish retain periodic rhythm

Question 19

melanopsin

Answer 19

photosensitive pigment in RGC’s - respond to blue light

Question 20

retinohypothalamic path:

Answer 20

1. retina
2. retinohypothalamic tract
3. optic chiams
4. SCN

Question 21

2 SCN subdivisions:

Answer 21

1. core (ventral) = non rhythmic
2. shell (dorsal) = rhythmic

Question 22

what are the 2 groups of circadian neurons? functions?

Answer 22

m cells = require light, control morning activity
e cells = require darkness, control evening activity

Question 23

are SCN endogenous rhythm’s learned?

Answer 23

no - animals still exhibit rhythmic behaviour

Question 24

what does the SCN pacemaker drive?

Answer 24

slave oscillators

Question 25

slave oscillators:

Answer 25

control rhythmic occurrence of one behaviour ex: motor activity, eating, body temp

Question 26

melatonin:

Answer 26

promotes sleep, influences rest and digest system (PNS)

Question 27

where is melatonin released from?

Answer 27

pineal gland - circulates during dark phase *inhibited in spring, activated in winter

Question 28

where are glucocorticoids released from?

Answer 28

adrenal glands - circulate during light phase

Question 29

glucocorticoids:

Answer 29

mobilize glucose for cellular activity - support arousal responses in SNS

Question 30

beta waves: when? type?

Answer 30

- waking state - small amplitude, fast frequency

Question 31

alpha rhythm: when? type?

Answer 31

- relaxed state - larger amplitude, slower frequency

Question 32

what is N1 sleep? what waves do we see?

Answer 32

- drowsy state, sleep onset - theta, mixed waves

Question 33

what is N2 sleep? wave type?

Answer 33

- asleep - stable theta waves *occasional sleep spindles and K-complexes

Question 34

what is N3 sleep? wave type?

Answer 34

- deep sleep - delta waves (large amplitude, slow frequency)

Question 35

what is REM sleep? wave type?

Answer 35

- dreaming - beta waves - atonia

Question 36

how long are periods of sleep states? how many/ night?

Answer 36

- 90 minutes - 5/ night

Question 37

what occurs in body during NREM sleep?

Answer 37

- decrease body temp, HR, blood flow, BW - increase in growth hormones - maintain muscle posture - less vivid dreams

Question 38

what occurs in the body during REM sleep?

Answer 38

- regulatory mechanisms stop - atonia = motor neurons inhibited, some twitches

Question 39

Freud's theory of what dreams are?

Answer 39

symbolic fulfillment of unconscious wishes

Question 40

Jung's theory of what dreams are?

Answer 40

expressions of our collective unconscious

Question 41

what are most dreams we have related to?

Answer 41

recent events and concern ongoing problems

Question 42

bottom up dream interpretation: activation synthesis

Answer 42

- dreams are meaningless brain activity - cortex generates images from personal memory

Question 43

top down dream interpretation: coping hypothesis

Answer 43

- dreams lead to adaptive performance when dealing w threatening events - problem solving - "sleep on it"

Question 44

when does sleep paralysis typically occur?

Answer 44

when stressed out

Question 45

how does lucid dreaming differ?

Answer 45

- you're in control - positive, coping

Question 46

what can promote lucid dreaming?

Answer 46

ACh agonists

Question 47

how is sleep a biological adaptation?

Answer 47

- energy -conserving strategy - animals w/ nutrient rich diets spend more time sleeping - can't see well at night = sleep

Question 48

BRAC - basic rest activity cycle

Answer 48

- recurring cycle of temporal pockets ( ~90 min in humans) where animal's level of arousal waxes and wanes

Question 49

what are the restorative properties of sleep?

Answer 49

- chemical events that provide energy to cells may be reduced during waking, are replenished during sleep

Question 50

3 phases of memory storage:

Answer 50

1. encoding 2. consolidation 3. recall

Question 51

encoding aka labile phase

Answer 51

new memory encoded

Question 52

consolidation phase

Answer 52

relatively permanent representation of memory solidified

Question 53

recall phase

Answer 53

neural networks that represent memory are activated

Question 54

multiple process theories

Answer 54

different kinds of memory are stored during different sleep states

Question 55

sequential process theories

Answer 55

memory is manipulated in different ways during sleep states

Question 56

storage process theories

Answer 56

brain regions that handle different kinds of memory during waking continue to do so during sleep