Sleep and hypnotics

Question 1

What is sleep?

Answer 1

A readily reversible state of reduced responsiveness to, and interaction with, the environment

Question 2

What is obtundation?

Answer 2

a state of consciousness from which only painful stimuli will return the patient to full consciousness

Question 3

Functions of sleep?

Answer 3

Restorative, protective adaptation, metabolism/weight homeostasis, memory consolidation and integration

Question 4

What is restored during sleep?

Answer 4

cortical recovery and tissue repair

Question 5

Why is sleep a protective adaptaiton?

Answer 5

protection from nocturnal predators

Question 6

What does an electroencephalogram (EEG) record?

Answer 6

The activity of populations of neurons in the brain

Question 7

What does the frequency of an EEG show?

Answer 7

How fast the neurons are firing

Question 8

What does the amplitude of an EEG show?

Answer 8

The amount of neurons firing in synchrony

Question 9

What does an EEG sum show?

Answer 9

The summed activity from multiple electrodes

Question 10

What does it mean for nerve cells to be synchronised?

Answer 10

They are all firing together

Question 11

What are the amplitude and frequency characteristics of desynchronised neurons?

Answer 11

Fast wavelength, low amplitude

Question 12

What are the amplitude and frequency characteristics of synchronised neurons?

Answer 12

Slow wavelength, large amplitude

Question 13

Delta rhythms?

Answer 13

Slow (4Hz) and large amplitude, deep sleep

Question 14

Theta rhythms?

Answer 14

SLow (4-7Hz), light sleep

Question 15

Alpha rhythms?

Answer 15

Fast ish (8-13Hz), conscious relaxation

Question 16

Beta rhythms?

Answer 16

fastest (>14Hz), awake and alert

Question 17

Gamma oscillations?

Answer 17

Memory encoding, recall and attention

Question 18

Two categories of sleep?

Answer 18

Rapid eye movement (REM) and non-rapid eye movement (NREM)

Question 19

REM characteristics?

Answer 19

~20 mins, dreaming

Question 20

NREM length

Answer 20

60-90 mins

Question 21

What happens to the length of NREM stages as you progress through the night

Answer 21

gets shorter

Question 22

What happens to the length of REM stages as you progress through the night

Answer 22

gets longer

Question 23

Awake rhythms?

Answer 23

alpha and beta

Question 24

How long does stage one NREM sleep last?

Answer 24

5 min

Question 25

Type of rhythms in REM sleep?

Answer 25

beta

Question 26

Stage 1 NREM characteristics?

Answer 26

5 mins, theta rhythms, starting to fall asleep, nerves begin to become synchronized

Question 27

Stage 2 NREM characteristics?

Answer 27

1-15 mins, spindle and k complex rhythms

Question 28

Stage 3 NREM characteristics?

Answer 28

5-25 mins, no eye/body movements, delta rhythms, restorative sleep

Question 29

Stage 4 NREM characteristics?

Answer 29

Deep sleep, 20-40 mins, delta rhythms

Question 30

What is the EEG of REM sleep similar to?

Answer 30

an active, waking brain

Question 31

When does dreaming occur?

Answer 31

REM sleep

Question 32

What is REM sleep referred to as?

Answer 32

An active, hallucinating brain in a paralysed body

Question 33

What kind of nerve activity predominates in REM sleep?

Answer 33

sympathetic

Question 34

What is increased in REM sleep as a result of sympathetic activity?

Answer 34

Heart rate, respiration rate and blood flow to the penis

Question 35

Changes in NREM sleep?

Answer 35

muscle tension reduced, temp lowered, energy consumption lowered, more parasympathetic activity

Question 36

What area of the brain is important for control of sleep?

Answer 36

Reticular activating system

Question 37

What are thalamo-cortical inputs used for?

Answer 37

controlling sleep

Question 38

What happens if you stimulate the reticular activating system in the brainstem?

Answer 38

wake up an animal

Question 39

Which brain areas make up the reticular activating system?

Answer 39

Locus coeruleus, raphe nuclei, brainstem/forebrain, midbrain

Question 40

What are all the areas that are part of the RAS involved in?

Answer 40

Amine NT secretion

Question 41

Increased firing of the RAS neurons is associated with?

Answer 41

waking up

Question 42

Decreased firing of the RAS neurons is associated with?

Answer 42

falling asleep

Question 43

Amine NT associated with locus coeruleus?

Answer 43

noradrenaline

Question 44

Amine NT associated with raphe nuclei?

Answer 44

serotonin

Question 45

Amine NT associated with brianstem/forebrain?

Answer 45

ACh

Question 46

Amine NT associated with midbrain?

Answer 46

histamine

Question 47

What is the activity of the RAS regulated by?

Answer 47

Hypothalamus

Question 48

Which neuropeptide is expressed in the hypothalamus that helps regulate the RAS?

Answer 48

orexin

Question 49

What does orexin do?

Answer 49

Stimulates RAS activity

Question 50

What causes decreased firing of RAS neurons

Answer 50

GABA

Question 51

What are "REM on" neurons?

Answer 51

cholinergic neurons in the brainstem

Question 52

What are "REM off" neurons?

Answer 52

Serotonergic and noradrenergic neurons in the brainstem

Question 53

RAS thalamus cortical interactions of an awake brain?

Answer 53

Awake--> RAS activates thalamus--> thalamus generates non-rhythmic activity--> cortex entrained into fast waking activity

Question 54

RAS thalamus cortical interactions of an asleep brain?

Answer 54

Asleep--> RAS activity switched off--> thalamus generates rhythmic activity--> coretex entrained into slow sleep rhythms

Question 55

Possible effects of insomnia?

Answer 55

Difficulty getting to sleep, difficulty staying asleep or feeling sleepy when having had sleep

Question 56

What do drugs that can help you sleep target?

Answer 56

GABA

Question 57

Why is GABA targeted by sleepy drugs?

Answer 57

GABA can inhibit the RAS,

Question 58

What is decreased activity of RAS associated with?

Answer 58

Falling asleep

Question 59

What kind of modulators of GABAa are benzodiazepines?

Answer 59

allosteric

Question 60

Nitrazepam and flurazepam are?

Answer 60

Long acting benzodiazepines

Question 61

Loprazelam and temazepam are?

Answer 61

Short acting benzodiazepines

Question 62

What differentiates the acting time of benzodiazepines used to treat sleep issues?

Answer 62

The metabolism time of them (short acting are metabolized quickly)

Question 63

What are the Z drugs?

Answer 63

Zolpidem, zolpiclone, zalpeon

Question 64

Action of z drugs?

Answer 64

bind at GABA and enhance endogenous activity of GABA

Question 65

What are orexin antagonists used for?

Answer 65

hypnotics

Question 66

Where is melatonin secreted from?

Answer 66

pineal gland

Question 67

What does melatonin regulate?

Answer 67

circadian rhythms

Question 68

Rising melatonin levels means?

Answer 68

Need to go to sleep

Question 69

Narcolepsy?

Answer 69

Pathological increase in sleep, sudden onset of sleep and sudden loss of motor control

Question 70

What may cause narcolepsy?

Answer 70

Reduced numbers of orexin neurons, loss of RAS activation