Reticular Activating System Flashcards
Reticular Activating System is a network of nerve cells in brain stem transmitting _____and_____stimuli
environmental and sensory
we will_____ if RAS loses its function
lose consciousness
the ascending tract____ the reticular formation while the descending tracts can either give off______ signals or____ signals
activates
inhibitory
fascilatory
ASCENDING RAS
- projects into cerebral cortex in 2 ways
- through_____
- through_____
- begins in the____ part of the brain stem
- extends upwards through___,____,____ and finally projects throughout the_____
sub-thalamus
thalamus
lower
pons ,midbrain, thalamus
cerebral cortex
Ascending RAS Is a specific System
T/F
F
Non-specific
ARAS can be activated by jUst 1 sensory stimuli
T/F
F
Different plenty stimuli
All sensory stimuli project their collaterals to RAS
T/F
T
RAS also Receives afferent from spinal cord
T/F
T
RAS sends impulse to all areas of cerebral cortex+other parts of brain
- part of it Bypasses the ___ to project diffusely to the cortex
- Other part ends in the_____ and related ____ nuclei and later projects_____ to the neocortex
thalamus
intralaminar
thalamic
nonspecifically
Non-specific projection of RAS into the cortex is responsible for____,____,_____
arousal, alertness and wakefulness
DESCENDING RETICULAR ACTIVATION SYSTEM
Can either be ___ or _____
Inhibitory
Fascilatory
DESCENDING RETICULAR ACTIVATION SYSTEM
INHIBITORY
-____ muscle tone
FACILITATORY
______ muscle tone
Regulates
Maintain
DESCENDING RETICULAR ACTIVATION SYSTEM
INHIBITORY
____ARAS
FACILITATORY
_____ARAS
Inhibit
Activate
Which component of the RAS is involved in Smoothness and accuracy of voluntary movements
DRAS - inhibitory
Ascending RAS receives inhibitory input from___ hypothalamus and _____ nuclei,____
posterior
thalamic
medulla
Which component of the RAS is involved in Maintenance of posture
DRAS - inhibitory
Which component of the RAS is involved in Facilitates autonomic functions
DRAS - facilitatory
Which component of the RAS is involved in Control of vegetative functions
DRAS inhibitory
Which component of the RAS is involved in Reflex movements
DRAS inhibitory
FUNCTIONS OF RAS
-_____fibers controls overall degree of cortical alertness or level of consciousness (maximum;wakefulness;sleep;coma)
ascending
RAS is a sophisticated____ that____ and acts like an_____
filter
screens out the junk
executive assistant
the RAS allows you to focus on what you value
T/F
T
RAS Doesn’t allow you to perceive a threat immediately
T/F
F
It does
RAS supports you when you set goals
T/F
T
How RAS affects sleep
Sleep-wake transition:provides____ influence on external stimuli by______ during sleep.
an inhibitory
reducing afferent (sensory neurons) activity
Neurons in RAS have a higher/lower firing rate during wakefulness ??
Higher
medical procedures: anesthetics affect consciousness by______
turning off the RAS.
Malatonin affects the RAS
T/F
T
Damage to RAS could result in____, sleep disorders like_____,chronic fatigue,______
coma
narcolepsy
attention deficit disorder
What is narcolepsy???
chronic sleep disorder that causes overwhelming daytime drowsiness
Neurotransmitters in RAS
- norepinephrine
- acetylcholine
- serotonin
- dopamine
- histamine
- ______
- gaba
- ______(_____)
galanin
orexin; hypocretin
