Post on 18-Jan-2020
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Nervous System
Nervous System
CNS-Central Nervous System
Control stimulates and coordinates all other
body systems
Command center
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Nervous System
PNS-Peripheral nervous system
Nerves outside the brain and spinal cord
Nervous System
ANS-Autonomic nervous system
responsible for control of the bodily functions
not consciously directed
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Nervous System
Fundamental unit of nervous tissue is the
neuron
Neuron is a nerve cell that includes the
dendrites and axons.
Nervous System
Dendrite- fiber branches that receive
impulses from other parts of the nervous
system and bring it to the cell.
Axons- transmit the impulses away from the
cell body. COLOR BK PG 13
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Nervous System
Myelin- fatty sheath surrounding the axon.
Speeds up impulse conduction.
Grey Matter is unmyelinated fiber, in the
cerebral cortex and central spinal cord
White matter is myelinated fiber within spinal
cord and fiber systems. COLOR BK PG 13/77
Nervous System
Synapse- transmission of impulses from one
neuron to another occurs at here.
COLOR BK PG 70
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Nervous System
Afferent neuron- sensory neuron takes the
message from the skin to the brain. Or
periphery to the CNS. COLOR BK PG 69
Nervous System
Efferent Neuron- motor neuron that takes the
message from the brain to the muscle. Or
CNS to the periphery. COLOR BK PG 69
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Nervous System-CNS
Central Nervous System is made up of the
Brain and spinal cord.
Brain is made up of the
cerebrum, brainstem
and
cerebellum.
Nervous System
Cerebrum is the largest and main portion of
the brain, it is responsible for the highest level
of function. It has four lobes.
COLOR BK PG 73
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Nervous System
The four lobes each have different functions.
Nervous System
Thalamus is inside the cerebrum, this is
where the nerve cells relay body sensations,
where pain is perceived. COLOR BK PG 75
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Nervous System
Cerebellum means “little brain.” The main
function is to control muscle coordination,
tone and posture. COLOR BK PG 76
Nervous System
Brainstem has three parts, the midbrain,
pons, and medulla. COLOR BK PG 76
Midbrain is center for visual reflexes
Medulla is the center for automatic control of
respiration and heart rate.
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Nervous System
Brain Protection
Skull- bones with fused joints for greater
strength of protection. COLOR BK PG 22
Nervous System
Brain Protection-three membranes-meninges
Dura mater-outer thickest layer that means in
latin COLOR BK PG 81
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Nervous System-Injuries
Nervous System
Brain Protection-three membranes-meninges
Arachnoid mater- middle layer
Subarachnoid space- where the shock
absorbing cerebrospinal fluid is located.
Pia mater- carries blood
vessels to the brain.
COLOR BK PG 81
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Nervous System
Spinal Cord is 17 inches long (approximate)
Has the same 3 protective layers as the brain
Outer dura mater
Arachnoid memebrane
Inner pia mater
Cerebrospinal fluid flows
between arachnoid layer
and pia mater
Spinal cord and spinal nerves
COLOR BK
PG 86
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VERTEBRAE AND SPINAL
CORD/NERVES
Vertebrae
Vertebral Foramen-passageway for the spinal
cord.
Intervertebral foramen- sides of the vertebral
column, where the spinal nerve roots exit the
vertebral canal COLOR BK PG 25
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Peripheral Nervous System
The part of the nervous system outside of the
vertebral column:
Cranial Nerves
Spinal Nerves
Peripheral Nervous System
Cranial Nerves have origin in the brain.
They are sensory nerves, motor nerves or
mixed.
Sensory- I, II, VIII,
Motor- III, IV, VI, XI, XII
Mixed V, VII, IX, X
COLOR BK PG 83
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Peripheral Nervous System
The cranial nerves are:
1.CN I - Olfactory Nerve
2.CN II - Optic Nerve
3.CN III - Oculomotor Nerve
4.CN IV - Trochlear Nerve
5.CN V - Trigeminal Nerve
6.CN VI - Abducens Nerve
7.CN VII - Facial Nerve
8.CN VIII - Vestibulocochlear Nerve
9.CN IX - Glossopharyngeal Nerve
10.CN X - Vagus Nerve
11.CN XI - Spinal Accessory Nerve
12.CN XII - Hypoglossal Nerve
Oh
Oh
Oh
To
Touch
And
Feel
Very
Good
Velvet
Such
Heaven
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Spinal Nerves
There are 31 pairs of spinal nerves.
8 cervical-exit above their vertebrae
12 thoracic-exit below their vertebrae
5 lumbar
5 sacral
1 coccygeal
COLOR BK PG 86
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Spinal Nerves
Plexuses- network of nerves
Root/Trunk/Cord/Peripheral nerves
COLOR BK PG 87
Another Brachial Plexus Picture
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Spinal Nerves
There are 3 plexuses
Cervical Plexus- make up C1-C4
Brachial Plexus- make up C5-T1
Lumbosacral Plexus- make up L1-S5
COLOR BK PG 87
Spinal Nerves
FUN FACT!
Most muscles are inervated by at least 2
spinal nerves so loss of function will not
occur, likely the muscle will weaken
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Spinal Nerves
FUN FACT!
Significant levels
C3- damage here or above would affect
function of the diaphragm. Need assistance
with breathing.
C5- damage from here down would result in
loss of upper extremity function.
Spinal Nerves
Dermatomes- COLOR BK PG 89
Area of skin supplied with the sensory fiber of
a spinal nerve.
Most areas have overlap, so total anesthesia
will not occur unless 2 nerves lose function.
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Spinal Nerves