Download Chapter 12 Central Nervous System – Brain

Chapter 12 Central Nervous System – Brain
CNS as integration of arcs
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integration center
interneurons
parallel circuits
brain
spinal cord
connect “appropriate” motor responses to stimuli
also: learning
memory
Central Nervous System
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brain
control center
spinal cord
superhighway
gray matter
cell bodies and interneurons
white matter
axons and dendrites
brain functional areas
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integration areas
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connect
sensory to motor
sensory to sensory
other areas
(parallel)
Brain
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cerebrum
cerebellum
diencephalon
• thalamus
• hypothalamus
• epithalamus
brain stem
• midbrain
• pons
• medulla oblongata
cerebrum functional areas
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motor
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conscious motor
frontal
eye movement
frontal
speech movement
frontal (Broca’s area)
sensory
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general sensation
parietal
auditory
temporal
visual
occipital
taste
parietal
olfactory
temporal , limbic system
other functional structures
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cerebellum
coordination of voluntary motor
synergist - antagonist
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basal ganglia
motor control
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thalamus
sensory relay
sensory filtering
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hypothalamus
visceral control
Hypothalamus
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visceral control center
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regulates bodily functions
temperature
hunger
glucose, amino acids
thirst
salts, water
pH levels
CO2
Autonomic NS
emotions
visceral responses
endocrine
controls Pituitary gland
brain stem
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3 parts :
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midbrain
pons
medulla oblongata
vital functions
passageway betw cortex and spinal cord
cranial nerves
midbrain
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cranial nerves nuclei
III , IV
corpora quadrigemina
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superior colliculi
visual reflexes
inferior colliculi
auditory reflexes
substantia nigra
influences basal ganglia
produces Dopamine
pons
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cranial nerves nuclei
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respiratory centers
V , VI , VII
medulla oblongata
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cranial nerve nuclei
VIII, IX, X, XI, XII
visceral motor nuclei
cardiac center
HR
vasomotor center BP
respiratory center resp rate
reflexes
swallow
cough
sneeze
BP , HR , Resp
limbic system
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medial surface of each hemisphere
emotional brain
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amygdala
fear, anger
cingulate gyrus
emotions, gestures
memory / learning
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hippocampal formation
short term memory
sends to cortex (LTM)
amygdala
memories of emotions
hypothalamus
visceral responses
frontal lobe
social behaviors
Brain Waves
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measure of electrical activity
EEG = electroencephalogram
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locates lesions
inactivity – increase amplitude
active – complex, low amplitude waves
Alpha waves 8-13Hz relaxed wakefulness
Beta waves
14-25Hz alert, concentrating
Theta waves 4-7Hz
abnormal (adults)
Delta waves < 4 Hz deep sleep, abnormal if awake
consciousness
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sensation
change in ion permeability due to a stimulus
perception
conscious awareness of a sensation
Brain is the organ of perception
light stimulates receptors
vision
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sensation
our perception of that sensation
motor responses w/o consciousness:
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plants ; stretch reflex ; BP ; light reflex
problems of consciousness
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syncope
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coma
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brief unconsciousness
unresponsive to sensory stimuli
not deep sleep
decreased O2 use
may include part of brain stem
sleep
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partial unconsciousness
cerebral, not brain stem
can respond to stimuli
decreased RAS activity
 adenosine
increase after ATP use
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Why sleep?
restore NT’s
organize memories , emotions
“we dream to forget”
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insomnia
types of sleep
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NREM
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slow-wave sleep
delta waves
low vitals
increase digestive activity
REM
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non-rapid eye movement
4 stages
rapid eye movement
alpha waves
irregular
increase vitals
decrease digestive functions
skeletal muscles inhibited
limbic system active
dreams
memory
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learning
changes in synaptic communication
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memory
those changes lasting a long time
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declarative
memory
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facts , events
short term memory
long term memory
non-declarative
motor skills, procedures
how do we store memory ?
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synapses work better
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LTP
long term potentiation
potentiates neural connections
• sensory - sensory
• sensory – motor
connect “appropriate” motor responses to stimuli
build networks
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associations
reverberating circuits
result
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synapses work better
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LTP
more NT receptors
• glutamate
- NMDA - Ca
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 NT production
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dendritic spines change shape
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greater chance of action potential
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•  strength of graded potentials
where is the memory ?
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middle temporal lobe
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hippocampus
STM
consolidation
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amygdala
fear, danger ; and responses
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cerebral association areas
sensory info
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prefrontal cortex
behaviors
affects on memory
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repetition
increase LTP
association
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networks
stress
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norepinephrine
glucocorticoids
glutamate
sleep
alcohol
memory problems
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amnesia
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anterograde amnesia
new info
retrograde amnesia
old info
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post-traumatic stress disorder
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Alzheimer’s
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Hippocampus
cerebral cortex
change NMDA receptors and Ca++ influx
decreased Ach production
plaques : beta amyloid peptide
stem cells
neurogenesis