Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

1.1.3 The Human Body > 6. Sleep > Flashcards

6. Sleep Flashcards

1
Q

Circadian Rhythm

A

The sleep to waking cycle which takes place over the course of a day (around 24 hours)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Zeitgebers

A
  • Environmental cues which control the timing of circadian rhythms
    • The daily light-dark cycle
      • Not necessarily 24 hours - we can engineer our circadian rhythms by changing light-dark exposure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Free-running rhythms

A

Circadian rhythms that continue to exist in environments with no environmental cues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Free-running period

A

The duration of free-running rhythms
Generally a little longer than 24 hours (our biological clocks run a little slow without environmental cues)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Internal desynchronization

A
  • Individuals in the same, constant environments do not always share sleep-wake and body temperature cycles
  • Free-running period can change seemingly randomly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Suprachiasmatic Nuclei

A

Contains a circadian timing mechanism
an area in the medial hypothalamus supposedly controlling our circadian cycles

  • Timing mechanisms are controlled by the firing patterns of SCN neurons
    • Inactivity at night
    • Fire at dawn
    • Fire slowly & steadily all day
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Circadian Clock

A

Circadian cycles are controlled by internal timing mechanisms, free-running rhythms provide evidence for this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Retinohypothalamic tracts

A

Visual axons crucial in entraining light-dark driven circadian rhythms
Convey information about how much light there is in the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Retinol ganglion cells

A
  • Key to entraining circadian rhythms
  • Evolved to be sensitive to slow changes in background illumination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Melatonin

A
  • Produced in the pineal gland
  • Releases a melatonin to help influence circadian rhythms
  • Synthesized from serotonin
  • Adjusts the timing of internal biological clock
    • Chronobiotic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Recuperation Theories

A

We sleep to restore homeostasis, which was disturbed while awake

Most common/Main theories
1. We sleep to restore energy depleted while awake
2. We sleep to clear toxins from the brain built up while awake

  • We wake when homeostasis has been achieved
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Adaptation Theories

A

We sleep as a result of our internal, 24-hour body clocks, regardless of events during wakefulness

Evolutionary
- We slept to conserve energy and because we functioned less well in the dark

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Sleep deprivation

A

Being unable to return to homeostasis affects stress, concentration, memory, mood & ability to complete complex tasks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Stage 1 Sleep (NREM 1)

A

Theta waves - irregular, jagged, low-voltage brain waves
4-7 Hz
Brain activity - less relaxed than wakefulness but more so than other sleep stages

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Stage 2 Sleep (NREM 2)

A

K-complex
Sleep spindle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Sleep spindle

A

a burst of 12- to 14-Hz brain waves associated with consolidation of memory
1. Result from interactions between cells in the thalamus and cortex
2. More spindles = improvements to memory

17
Q

K-complex

A

sharp wave associated with temporarily inhibiting neuronal firing

18
Q

Slow Wave Sleep (NREM 3)

A
  1. Delta waves
  2. Decrease in heart rate, breathing rate and brain activity
  3. Increase in slow, large-amplitude waves
    1. Indicates high synchronization in neuronal activity
    2. Compared to stage 1 & being awake where substantial activity in the cortex is continued
19
Q

REM Sleep

A

Rapid eye movement sleep
- Emerging stage 1
- REM sleep occurs when we’ve cycled back to stage 1

Elements of light and deep sleep
Increase in cerebral activity
Increase in variability of autonomic nervous system

  • Strengthening of emotional memories
  • Where most dreaming occurs
20
Q

Default Theory of REM Sleep

A

Difficult to stay in REM sleep so the brain switches to other stages throughout the night)

21
Q

Activation Synthesis Hypothesis (Dreams)

A

Random information & neural signals supplied to the cortex during REM so it forms dreams to make sense of them

22
Q

Neurocognitive Hypothesis

A
  • Dreams are thoughts taking place under unusual conditions
    • Parts of the parietal, occipital and temporal cortex experience stimulation which develops into a hallucination
  • No input from regular sensory sources means the brain generates images without context
  • Forgetting dreams & forgetting within dreams - suppression in the prefrontal cortex (working memory)
23
Q

Reticular Formation

A

A structure extending from the medulla into the forebrain which regulate arousal
- Pontomesencephalon - part of reticular formation contributing to cortical arousal
- Neurons receive sensory input & generate activity

24
Q

Locus Coeruleus

A

A small structure in the pons which emits bursts of impulses at emotionally arousing/meaningful events
- Releases norepinephrine throughout the cortex
- Increases activity in more active neurons, decreases activity in less active neurons
- This results in enhanced memory & attention to important information

25
Q

Hypothalamus

A
  • Contains neurons promoting sleep & wakefulness
    Posterior hypothalamus - Wakefulness
    Anterior hypothalamus - Sleepiness
  • Basal forebrain
    • Pathways in the lateral hypothalamus regulate cells here
    • Some cells increase wakefulness, others inhibit it
26
Q

GABA (neurotransmitter)

A
  • released in some cells, promoting slow-wave sleep (NREM 3)
  • Inhibitory effect on synapses, slowing down activity

In reticular formation

27
Q

Histamine

A
  • Neurotransmitter enhancing arousal & alertness
  • Antihistamines passing through the blood-brain barrier counteract this, producing drowsiness
28
Q

Orexin/Hypocretin

A
  • Released from lateral and posterior nuclei
  • Enhances wakefulness & activity
    • Not for waking up but for staying awake
29
Q

Serotonin & Norepinephrine

A

Interrupting REM sleep

30
Q

Acetylcholine

A
  • Learning, retention
  • Shift from NREM sleep to REM sleep
31
Q

Polyphasic sleep cycles

A

common in mammals and human infants, they regularly sleep more than once per day

32
Q

Monophasic sleep cycles

A

most human adults, they sleep once per day

33
Q

Naps

A

Methods suggest polyphasic sleep cycles may be effective

1.1.3 The Human Body (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions