Transcript CNS system PartII

Supplemental instruction
CNS system
Part II
•Forebrain
•Midbrain
•Hidbrain
Picture from http://hopes.stanford.edu/basics/braintut/ab3.html
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Developmental categorization of CNS system.
-Forebrain ~ telencephalon ~ forming hemispheres of cerebrum.
diencephalon ~
-Midbrain ~ does not subdivide.
-Hindbrain ~ metencephalon ~ pons, cerebellum
myelencephalon ~ Medulla oblongata, RAS
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Forebrain
-comprised of cerebrum and
diencephalon
-Involved in emotion, learning
and memory
____________
Cerebrum
-Regulate sensory info and
motor response.
-Basal nuclei in deep region.
____________
Diencephalon
-Thalamus/epithalamus
-Hypothalamus
-Pituitary gland
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Diencephalon (in forebrain)
-Thalamus/epithalamus(pineal gland)
-Hypothalamus
-Pituitary gland
Thalamus
_________
- relay center to cerebrum
all sensory information except smell
epithalamus
__________
- includes pineal gland which secrets
melatonin.
_____________
Hypothalamus
- integrates nervous and endocrine systems
- Regulates anterior and posterior pituitary glands.
- Hunger and thirst, body temperature, emotions
-coordinate autonomic and endocrine responses.
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Pineal gland
SCN (suprachiasmatic nucleus)
-regulate ______________
Circadian rhythms(biological clock)
-Adjusted daily by light from eyes.
-Controls pineal gland secretion of
__________
melatonin to regulate circadian rhythms
*Melatonin is involved in aligning
physiology with sleep/wake cycle and
seasons.
-Secreted at night
-Inhibited by light
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Choose Thalamus, Hypothalamus, Epithalamus
Thalamus
________
-relay center to cerebrum all sensory
information except smell alertness.
-Role in level of arousal.
Hypothalalmus
____________
-integrates nervous and endocrine systems(hormone).
-contains neural centers for hunger, thirst, body
temperature.
Epithalamus
___________
-contains choroid plexus and pineal gland.
choroid
plexus secretes CSF.
____________
pineal gland
____________
secretes melatonin
*Melatonin: involved in sleepDesigned
cycle
and seasonal reproduction.
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Midbrain
-visual and auditory reflexes
-connects with cerebrum and
cerebellum; motor reflexes
- Superior colliculi, Inferior colliculi,
Red nucleus , substantia nigra
Superior colliculi - involved in visual reflexes
______________
______________relay auditory information
Inferior
colliculi
Red
nucleus and substantia nigra involved in motor coordination
_______________________-
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Dopaminergic pathways
-Neural pathways in the brain
which transmit the
neurotransmitter __________.
dopamine
-Motor coordination
•Mesolimbic dopamine pathway
- involved in reward and drug
addiction.
- Abused drugs cause dopamine release
from the nucleus accumbens.
*heroin and morphine- production
cocaine and amphetamines- inhibit reuptake
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•Nigrostiatal dopamine pathway
- Motor control pathway
Dopamine neurons in ______________
Substantia nigra degenerate in
Parkinson’s disease.
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Hindbrain
A: pons
C: Celebellum
B: Medullar oblongata
Contains______,
_______
medulla
pons _________,and
cerebellum
__________
cerebellum motor coordination; motor learning;
trained voluntary activity
__________
cerebellum ataxia caused by damage to this area.
A
B
Ataxia: Loss of the ability to coordinate muscular movement.
__________
Includes two important respiratory control centers
pons
________________
Medullar
oblongata several crucial centers for breathing and
cardiovascular systems.
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C
Hindbrain
Reticular Activating System (RAS)
___________________________
- an ascending arousal system.
- composed of several neuronal
circuits connecting the brainstem to the
cortex.
* Textbook says “…originates in groups of
neurons in the pons, midbrain reticular formation,
hypothalamus and basal forebrain.”
- promotes wakefulness, but inhibits
sleep.
- Regulating Sleep-Wake Transitions
-Stimulation in RAS causes wakefulness.
-Damage to RAS causes coma.
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Disorder in RAS
-Loss of general sense of
consciousness or wakefulness.
-result in alterations of sleep-wake
cycles and disturbances in arousal.
-Narcolepsy:excessive daytime sleepiness
-Coma
* Be careful!
RAS ~ Promotes wakefulness and
inhibits sleep at the day time!
Melatonin in pineal gland ~ Promotes
sleep at the night!
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