Transcript Nervous system

“Let’s get wired!”
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Central Nervous System – CNS
◦ Brain and spinal cord
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Peripheral Nervous System
◦ Outer region – cranial/spinal origination
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Afferent nerves – incoming senses
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Efferent nerves – outgoing motor
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Somatic - skeletal
Autonomic – visceral –
smooth/cardiac/glands
◦ Sympathetic – fight or flight response – immediate
threat
◦ Parasympathetic – resting/regroup activities
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Skull
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Meninges
◦ Dura - epidural/subdural space
◦ Arachnoid – subarachnoid space
◦ Pia
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Protection of the brain and spinal cord
Circulates chemicals for internal brain function –
ie. CO-2 changes will cause medulla oblongata to
accommodate respiratory function to meet body
needs for homeostasis
Mainly found in subarachnoid space and
ventricles (4) two in cerebrum, one medial/below
these, and one in cerebellum (brainstem)
Formed in choroid plexus – extracted from blood
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Formed in choroid plexus
Ventricles
Central canal/subarachnoid space
Absorbed back into the blood
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Normal adult CSF fluid is 140 ml
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CSF from subarachnoid space in L3-4
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Pt. in R/L lateral fetal position or sitting on
bedside
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Pt. remains flat X 12 hrs. after procedure
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Blood patch sometimes required
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Tests for infection, disease
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Congenital / tumor
Ventricles malfunction and disallow normal
CSF flow
1-3:1000 births
2. What is
“hydrocephalus”
and how can it
be treated?
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Protected by vertebral column
Extends from foramen magnum to the distal
end of the first lumbar (45 cm – 18 in.)
Spinal cavity includes: cord, blood vessels,
adipose tissue, meninges, and CS fluid
Split into two symmetrical halves – anterior
surface is deeper and wider than the
posterior surface
Nerve roots project from each side of cord
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Dorsal nerve root – sensory information to
cord
Ventral nerve root – motor information out of
the cord
Each side of the cord the dorsal and ventral
nerve roots join together to form a spinal
nerve (peripheral)
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Conducts information to and from the brain
Integrator – reflex center – for all spinal
reflexes
Refer to ascending/descending tracts pgs.
382-383
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One of the largest vital adult organs
Weighs 3 lbs.
100 billion neurons/900 glia (support cells) –
also called neuoglia
Mitotic division only occurs in-utero and first
few months post-natal
Cells will mature, but not increase in number
Maturity by 18 y.o.
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Medulla oblongata
Pons
Midbrain
Cerebellum
Diencephalon
Cerebrum
Composed of:
Medulla oblongata
Pons
Midbrain
Underside of the brain, showing the brainstem and cranial nerves
Internal view of the lower brain
Homonculus, a sensory map of your body. The homunculus looks rather
strange because the representation of each area is related to the number of
sensory neuronal connections, not the physical size of the area.
Homonculus, a sensory map of
your body. The homunculus
looks rather strange because the
representation of each area is
related to the number of sensory
neuronal connections, not the
physical size of the area.
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Attaches to spinal cord
An extension of the spinal cord above the
foramen magnum
One inch in size
Separated from the pons by horizontal groove
Controls cardiac, respiratory and vasomotor
function
Non-vital reflexes – vomiting, cough, sneeze
swallow
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Above the medulla oblongata
Motor control
Sensory analysis
Reflex mediator for the 5th-8th cranial nerves
Helps with respiratory regulation
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Mesencephalon
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Above the pons and below the cerebrum
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Vision, hearing, eye movement, body
movement
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Second largest part of the brain
Located below the posterior section of the
cerebrum
Responsible for movement coordination –
smooth, precise and steady as to force, rate
and extent
Posture
Balance – equilibrium receptors from ear
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Abscess, hemorrhage, tumor, trauma
Ataxia – muscle incoordination
Hypotonia
Tremors
Gait disturbance
Balance disturbance – staggering, lurching,
raising foot to high to step, bringing foot
down very hard
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Between the cerebrum and midbrain
Includes thalmus,hypothalmus, optic
chiasma, and pineal body
Also known as the “emotional brain” or limbic
system
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Processes auditory and visual signals
Relay station for sensory perception to
cerebrum
Conscious recognition of pain, temperature
and touch
Partly responsible for emotions by associating
sensory impulses with feelings of pleasant vs
unpleasant
Part in arousal/alerting mechanism
Part in complex reflex movement
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Autonomic center – visceral
Sense of smell
Link between mind and body
Pleasure/reward center – eating, drinking, sex
Relay station between cerebral cortex and autonomic
centers
Mind over matter philosophy – psychosomatic disease
– positive/negative
Regulates pituitary – renal function
Hormone regulation
Maintains wake state
Appetite regulation
Regulation of body temperature
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Above the midbrain
Looks line pine cone
Function not well understood
Regulates biological clock
Produces melatonin – synchronize various
body functions with each other and external
stimuli – such as onset of puberty and
menses – also helps with light perception –
called the “third eye”
Due next
class!
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Largest portion of the brain
Two halves separated by the longitudinal
fissure
Surface – gray matter 1/12-1/6” thick
Six layers containing millions of axon
terminals synapsing with dendrites and
neurons
Convolutions (gyrus)
Between gyri lie fissures (deeper grooves) or
sulci (shallow grooves)
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Fissues and imaginary boundaries divide each
hemisphere into 5 lobes
Four are named after cranial bone plates, the
fifth is called the insula (island of Reil) hidden
from view in the lateral fissure (see diagram
pg 391)
Interior of the cerebral cortex is the white
matter with a few small areas of gray matter
Known as basal ganglia
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Three tracts allow for communication within
the white matter
Projection – sensory and motor
Association – most numerous – from one
convolution to the other – same side
Commissural – from one hemisphere to the
other
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Pg.393
What part of the brain is injured if pt. exhibits
these symptoms:
Difficulty talking
Lack of hearing
Can’t feel hot temperature to fingers
Blurred vision
Slurred speech
Can’t move legs
Can’t stick out tongue
www.can-do.com/uci/ssi2001/cranial.html
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Touch, pressure, temperature, body position
(proprioception) – somatic senses
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Vision, hearing – special senses
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Combination of both senses helps the brain
to perceive images and relationships – (ie, ice
cube in the hand, nail in foot)
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Voluntary movements – complex – requires
great coordination of peripheral nerves and
cerebral cortex
Precentral gyrus in frontal lobe responsible
for most motor function
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Consciousness – state of awareness –
Mainly controlled through centers in the
brainstem (reticular activating system) and
thalamus receiving messages from the spinal
cord and then to the cerebral cortex
Without constant stimulation of the reticular
system, consciousness cannot be maintained
Certain drugs depress this system and
produce sleep – barbiturates
Drugs to stimulate this system are called
amphetamines
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Sleep
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5 stages -
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Two major divisions: Slow-wave sleep and Rapid
eye movement
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SWS – dreamless
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REM – dream state
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What is the difference between REM and
NREM sleep?
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Which one is only about 5 minutes?
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What phase of sleep produces radical an
crazy dreams?
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What is the purpose of sleep according to this
author?
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Anesthesia
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Drug induced
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Coma
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Trauma, disease, tumor growth, bleeding
Glasgow Coma Score
Eye Opening (E)
Verbal Response (V)
Motor Response (M)
4=Spontaneous
3=To voice
2=To pain
1=None
5=Normal conversation
4=Disoriented
conversation
3=Words, but not coherent
2=No words......only
sounds
1=None
6=Normal
5=Localizes to pain
4=Withdraws to pain
3=Decorticate posture
2=Decerebrate
1=None
Total = E+V+M
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Fetal position
Mumbling
Says “ouch” to pinch
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Smooth extension of arm when asked
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Stares at clinician
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No answer when asked name
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No response to pin prick
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Constant grunting sounds
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Face grimaced – eyes closed
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Meditation
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Higher wakeful state
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Provides relaxation/alertness
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Yoga
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Ability to speak and write words
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Frontal, parietal, temporal lobes
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Left hemisphere contains these areas in 90%
pop. – remaining 10% in right or both
Aphasia
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Latin - Border of fringe
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Medial surface of the cerebrum
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Anger, fear, pleasure, etc.
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Expression of emotion is combination of many
cortical structures
Rage is thought to occur when limbic activity is
not modulated by other cortical areas
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Major mental activities
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Short-term – seconds/minutes
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long-term – past occurrences
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Temporal, occipital, parietal
Bike
Arrow
Alligator
Kite
Butterfly
House
Flower
Hat
Nail
Coat
Skeleton
Nose
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Stem next to brain stem
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12 pairs
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Pass through a foramen
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Peripheral
Your group will
share with the
class.
Get into
groups of four
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Delta – slow - sleep
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Beta – fast – thinking actively
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Alpha – fast – relaxed/quiet
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During seizure, these waves are synchronized
and have rapid electrical spikes
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Stroke – interruption of blood flow
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Seizure – tumor, chemical imbalance, drugs,
idiopathic
Dementia – changes in brain function
1.
Alzheimer’s
2.
Huntington’s disease
3.
AIDS
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Creutzfeldt-Jacob disease
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Bovine spongiform encephalopathy – Mad cow
6.
Alcoholism
7.
Anemia
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FINISHED FILES
ARE THE RESULT OF YEARS
OF SCIENTIFIC STUDY
COMBINED WITH
THE
EXPERIENCE OF
YEARS...
I fear I am not in my perfect mind.
Methinks I should know you and know
this man;
Yet, I am doubtful; for I am mainly
ignorant
What place this is; and all the skill I
have
Remembers not these garments; nor I
know not
Where I did lodge last night. Do not
laugh at me.
(William Shakespeare (1605) King Lear,
Act IV, Scene 7)
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Runs – 2-25 year (usually 4-8)
Gradual degenerative disease
4.8 mil. Americans
Memory loss
Brain death of cells
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Genetic
Degeneration of nerve cells in the brain
tMT for emotional and movement problems
No cure
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1 per mil.
Familial
Confusion
Dementia
Progressive jerky movements
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Don’t eat cow!
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Groups of two - label the brain as to
function and control using various
colors to represent your learning
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Speech - red
Sight - dark blue
Hearing - light green
Touch - dark green
Sound - yellow
Movement - pink
Speech - black
Taste - orange
Brain Game ID
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Balance - brown
Posture – light blue
Coordinated muscle
movement - purple
Consciousness - red
Make a line in these colors to
indicate location and use an
identifying term