10-17 L1 Consciousness & sleep

Question 1

Content of consciousness

Answer 1

Specific senosyr inforamtoin received by the nervous system

Question 2

Level of Consciousness

(what are the two components)

Answer 2

• Arousability.alertness.wakefullness:
  
  • activation of cerebral cortex so that it is receptive to senosry input or ‘turned on’
• Awareness/orientation:
  
  • recognition of one’s temporal., spatial and personal relationships and environment
• note one can be alert (awake or arousable) without being aware (a computer is on but not processing)
• But one can’t be aware withouth being alert.( acomputer can’t process without being turned on)

Question 3

What type of signals does the Ascending reticular activating system (ARAS) send to the cortex?

Answer 3

• Direct
  
  • Pontomesencephalic reticular formation
• Indirect
  
  • thalamic intralaminar nuclei, basal forebrain and hypothalamus

Question 4

Lesion of what nucleus can induce insomina in rats?

Answer 4

Preoptic nuclei of the hypothalamus

Question 5

Where is the location of the Cholinergic cell groups?

Whats their function

Answer 5

• (MTN) Mesopontine tegmental nuclei of the rostral pons and midbrain
• Function:
  
  • Memory
  • Attention
  • sleep/wake cycle
    
    • Awake: active
    • NonREM: less active
    • REM: active

Question 6

Where is the location of Seotonergic cell groups?

What is their function?

Answer 6

• Raphe nuclie of the rostal brainstem
• Functions
  
  • Mood
  • Sleep/cycle
    
    • Awake: Active
    • Non-REM: less active
    • REM: quiesent

Question 7

A lesion of the raphe nuclei of the rostral brainstem would result in what (in cats)?

Answer 7

Random manifestatino of REM

• serotonergic cell groups (serotonin) is responsible for the timing of REM.

Question 8

Where is the location of Noradrenergic cell groups?

What is the function?

Answer 8

• Noradrenergic locus ceruleus
• Functions:
  
  • response to novel stimuli

Question 9

What is Sleep atonia?

Lesion of locus ceruleus will cause what?

Answer 9

• Sleep atonia: paralyzing the body during sleep so that we don’t move as we dream
• Lesion of locus ceruleus (in kittens) act out their dreams during REM

Question 10

Where is the location of histaminergic cell groups?

What is its function?

Answer 10

• Histaminergic tuberomammillary nucleus
• Function
  
  • Generla arounsal
  • themore active it is the more aroused you are

Question 11

What is the cause of cortical arousal?

What is the cause of cortical awareness?

what are the requirements for awareness?

Answer 11

• cortical arousal: activity of cortex due to input from the ARAS
• cortical awareness: Is activity of cortex due to thalamocortical & corticocortical processing (cognition)
• Awareness requires
  
  • awakeness
  • high fidelity transmission of senosry signals from thalamic relay nuclei to cortex.

Question 12

What part of the brain decides what input of the multiple channesl are aloowed to be processed.

Also can allow an all, none, or some of the information through

Answer 12

Thalamus

Question 13

T-type Ca²⁺ channels inactivated describes what?

Answer 13

Tonic or Relay mode

• High-fidelity relay
• low signal-noise ration
• IDeal for informtanoi processing

Question 14

T-type Ca²⁺ channels de-inactivated describes what?

Answer 14

Burst Mode

• Low fidelity relay
• High signal-noise ratio
• Ideal for search-light vigilance

Question 15

Dsecribes what happens during Wakefulness

Answer 15

• Wakefulness
  
  • multiple inputs from the ARAS depolarize thalamic neurons, shifting toward tonic mode.

Question 16

What happens in Slow-wave cycle?

Answer 16

• Slow-wave sleep
  
  • _ARAS activity is suppresed _
  • thalamic neurons switch into burst mode.

Question 17

What happens in REM sleep cycle?

Answer 17

• REM sleep
  
  • most ARAS activity is completely suppresed
  • however cholinergic activity is as great as during wakefulness
  • allowing thalamic neurons to remain in tonic mode.

Question 18

What happens in the following stages

• Awake
• Drowsy
• Stage 1
• Stage 2
• Stage 3-4
• REM sleep

Answer 18

• Awake
  
  • increased freq
  • decrease amp
• Drowsy
  
  • alpha waves
• Stage 1
  
  • theta waves
• Stage 2
  
  • Sleep spindles
  • K complex
• Stage 3-4
  
  • Delta waves >75
  • high amp
  • low freq
• REM sleep
  
  • PGO spikes (periodic pontine-geniculate-occipital
  • Sawtooth waves
  • high freq
  • low amp

Question 19

What type of sleep is seen in cases of brain injury and coma?

Answer 19

• Stage 3-4 sleep (delta waves)
• large slow brain wave associated with deep sleep
• during sleep delta waves are not present in other stages

Question 20

Based on internal arousibility what stage is the lightest stage of sleep?

Answer 20

REM

• REM sleep is more likely to result in spontaneous awakening
• stage 4>stage3>stage 2

Question 21

Pt is awaken from REM to find themselves temporarily paralyzed what would you diagnosis the pt with?

Answer 21

sleep paralysis

Question 22

What two muscles are not inhibited during sleep?

What is it called

what is it mediated by?

Answer 22

• extra-ocular mm and diaphram
• sleep atonia
• mediated by locus ceruleus

Question 23

What are the 3 things that change in sleep-cycles from young age to old age?

Answer 23

• REM sleep decreases slighty
• Stage 4 decreases progressively (so much that little or none is present in adults)
• elderly have frequent awakening and notable increase in wake time after sleep onset