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Flashcards in 19 Brain Arousal Systems - B Deck (45)
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1

What are the 2 parts of conciousness

Arousal and awareness

2

What are examples of arousal

Sleep and wakefulness

3

What is a minimally conscious state

Reproducible evidence of awareness exists but communication is limited

Sleep wake cycles can be seen on EEG

4

What is a persistent vegetative state

-pts eyes open and close
-they can track objects
-they can chew and swallow
-do not respond to auditory stimuli, pain, hunger

Good example of arousal but no awareness

5

What is a coma

Deeply unconscious and displays unresponsiveness to stimuli

May display reflexes

6

What marks irreversible brain death

No EEG activity recorded

7

What is required for arousal and awareness

Cortical function

8

Disruptions in consciousness arise from

Subcortical lesions
-brainstem
-midbrain
-hypothalamus

9

What are the excitatory amino acid arousal systems

-reticular activating system (RAS)
-parabracial nuclei (PBN)

10

What are the cholinergic arousal systems

Pedunculopontine tegmental and laterodorsal nuclei (PPT/LDT)

11

What are the noradrenergic arousal systems

Locus coeruleus (LC)

12

What are the serotonergic arousal systems

Raphe nuclei (RN)

13

What are the dopaminergic arousal systems

Ventral tegmental area (VTA)

14

What does the RAS project to

-hypothalamus
-thalamus
-cortex

15

What tract does the RAS descend to in spinal cord

Reticulospinal tract

16

What is the function of the RAS

-regulates arousal and consciousness
-all ascending (sensory) info goes through it
-modal specificity is lost because all pathways are converged
-USES GLUTAMINE

17

The ascending RAS has 2 outputs. Where do they go and what do they do

Ventral
-goes to cortex or through hypothalamus and then to cortex

Dorsal
-through thalamus and then diffuses to cortex

18

What is the parabrachial nuclei complex

Different neurons that play a role in promoting wakefulness through cortical activation \

19

What does the parabrachial nuclei do

Generates respiration patterns during waking state
-amygdala activation of PBN causes hyperventilation during anxiety
-USES GLUTAMINE

20

What are the PBN outputs

Ventral pathway (like RAS)
-goes straight to cortex or through hypothalamus to cortex

21

How is the PBN and RAS similar

Both use EAA glutamate
-RAS has interneurons that release GABA and ACh

22

Excitable amino acids are crucial to

Baseline excitation of cortical activity

23

What are the outputs of the PPT and LDT

Dorsal (to thalamus then cortex) or Ventral (to cortex or hypothalamus and then cortex)

24

What is the major neurotransmitter over the PPT/LDT

ACh

25

What nuclei are the primary cause wakefulness and REM sleep

Cholinergic nuclei

26

Also involved in wakefulness and REM sleep (beside LDT/PPT)

-noradrenergic neurons of locus ceruleus
-serotonergic neurons of raphe nuclei
-histaminergic neurons of the tuberomammilary nuclei (of hypothalamus)

27

What does antihistamines inhibit in the brain

TMN network to make you drowsy

28

In addition to sleep, cholinergic neurons also

Provide baseline excitation that is crucial to cortical activity

29

What is the locus coeruleus

Noradrenergic neurons that function in the alerting response

Being startled is also associated with this system

30

What are the functions of the locus coeruleus

-startle and alerting responses
-sleep-wake cycles
-behavioral vigilance