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NEUROLOGIC FUNCTION Anatomic and Physiologic Review
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Nervous System
CentralNervous
System (CNS)
Brain
andSpinal
Cord
PeripheralNervous
System (PNS)
Cranial nerves;
Spinal Nerves;and Autonomic
Nervous System
Sensory or
afferent
Motor or
efferent
Somatic motor Autonomic
sympathetic parasympathetic enteric
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D I V ISI ONS O F T H E N E R V O U S S YS T E M
CNS- integrates the information that it receives from,
and coordinates the activity of, all parts of the bodies
PNS- connects the CNS to limbs and organs
Sensory or afferent- conducts action potential from
sensory receptors to CNS
y Sensory neurons- transmits action potentials from
periphery to the CNS
Motor or efferent-conducts action potentials from CNSto effector organs
y Motor neurons- transmits action potentials from
CNS towards periphery
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D I V ISI ONS O F T H E N E R V O U S S YS T E M
Motor nervous system- transmits action potentials of
CNS to skeletal muscles
Autonomic Nervous System- transmits action
potentials from CNS to cardiac muscle, smooth muscle,
and glands.
Sympathetic- mobilize the body's resources
under stress; fight-or-flight response.
Parasympathetic- responsible for stimulation of
activities that occur when the body is at rest; rest-and-
digest.
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CE L LS O F T H E N E R V O US S YST EM
Neurons- basic functionalunit of the brain
Dendrites- branch-typestructures for receivingelectrochemical messages.
Axon- a long projectionthat carries electrical
impulses away from thecell body.
Myelinated sheath-increases speed of
conduction
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C E L LS O F T H E N E R V O US S YST EM
Ganglia or nuclei- nerve cell bodies occurring inclusters
Center- a cluster of cell bodies with the same
function
Neuroglial cells- serve to support, protect, and
nourish neurons.
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NEUROTR ANSMITTERS
Communicates messages from one neuron to another,or from one neuron to a specific target tissue
Manufactured and stored in synaptic vesicles.
Potentiates , terminates and modulates a specific
action, and it can either excite or inhibit activity of
target cell
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CNS: BR A IN
The Brain
y 2% of total body
weight,
approximately1400g for young
adult and 1200 in
elderly person.
y major areas:cerebrum, brain
stem, cerebellum,
and diencephalon.
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C N S : B R A I N
CERE
BELLU
My Means little brain
y Cerebellar penduncles- attached to the
brainstem by several large connections.
These connections provides routes of
communication between cerebellum and
other parts of the CNS.
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C N S : B R A I N
Diencephalon
y Thalamus
Influences mood and registers an unlocalized,uncomfortable perception of pain.
act as a relay between a variety of subcortical areasand the cerebral cortex
y Epithalamus
Involved in emotional and visceral response to odorsand pineal body.
Pineal body: an endocrine gland that may influence
puberty
y Hypothalamus
Plays an important role in maintaining homeostasis.
Control of body temp, hunger and thirst
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C N S : B R A I N
CERE
BRU
My Largest part of the brain
y Longitudinal fissure- divides cerebrum into
right and left hemisphere
y Gyri-numerous folds found on the surface of
hemisphere
y Sulci-intervening grooves
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C N S : B R A I N
Frontal lobes- control of voluntary motorfunctions, motivations, aggression, mood, and
olfactory(smell) reception.
Parietal lobes- principle center for the
reception and conscious perception of the
most sensory information, (touch,
temperature, balance and taste)
Central sulcus- separates the frontal and
parietal lobe
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C N S : B R A I N
Occipital lobe- functions in the reception andperception of visual input and is not distinctly
separate from the other lobes
Temporal lobe- involved in olfactory and
auditory hearing sensations and plays an
important role in memory.
Lateral fissure- separates most of the
temporal lobe from the rest of the cerebrum
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C N S : B R A I N
Brainstem- connects spinal cord to the remainder of the
brain.
y Medulla Oblongata-regulation of heart rate and blood
vessel diameter
Pyramids-transmits action potentials from brain to
motor neurons of spinal cord; is involved in
conscious control of skeletal muscle.
y Pons- (bridge)
relays information from between the cerebrum and
cerebellum
functions such as breathing , swallowing and
balance are controlled in the lower pons
Chewing and swallowing
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C N S : B R A I N
y Midbrain-Coordination of eye movement, control of pupil
diameter and lens shape.
Colliculi-mounds found on the dorsal part
Two inferior: relay centers for auditory nervepathways in the CNS pathway
Two superior: visual reflexes
Substantia nigra- black nuclear mass involved in
the regulation of general body movements.
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C N S : B R A I N
Meninges and CerebrospinalF
luidy Meninges- protects the brain and spinal cord
Dura mater: most thickest and superficial
surrounds the brain and the spinal cord and isresponsible for keeping in the cerebrospinal fluid.
Arachnoid: interposed between the two othermeninges
separated from the pia mater bythe subarachnoid space.
attached to the inside of the dura, surrounds thebrain and spinal cord but does not line the braindown into its sulci
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C N S : B R A I N
Pia mater: the delicate innermost layerenvelops the entire surface of the brain
supplies blood to the superficial areas of the
cortex and supports larger blood vessels passing
over the surface of the brain Astrocytes- anchors pia mater to the brain
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C N S : B R A I N
y Cerebrospinal Fluid-
a clear bodily fluid that occupies the
subarachnoid space and the ventricular
system around and insidethe brain and spinal cord
acts as a "cushion" or buffer for the cortex,
providing a basic mechanicaland immunological protection to the brain
inside the skull.
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CNS: SPINA L CORD
The Spinal Cordy Extends from the
foramen magnum at thebase of the skull to the2nd lumbar vertebra.
y Cauda equina: theinferior end of the spinalcord and the spinalnerves exiting there w/cresembles a horse·s tail.
y functions primarily inthe transmission of neural signals betweenthe brain and the rest of the body.
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CNS: SPINA L CORD
y contains neural circuits that can
independently control numerous
reflexes and central pattern generators
y The spinal cord has three major functions:
Serve as a conduit for motor information,
which travels down the spinal cord.
Serve as a conduit for sensory information,
which travels up the spinal cord.
Serve as a center for coordinating certainreflexes
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PNS: CR ANI A L NERVES
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No Name Gen. Function Specific Function
I Olfactory S Smell
II Optic S Vision
III Occulomotor M,P Eye movement, pupil constriction,
lens accommodation
IV Trochlear M Eye movement
V Trigeminal S,M Sensory to face and teeth ;
mastication
VI Abducent M Eye movement
VII Facial S,M,P Taste; facial expression; and
salivary & tear glands
VIII Vestibulocochlear S Hearing and balance
IX Glossopharyngeal S,M,P Taste and touch(back of tongue);
swallowing; salivary glands
X Vagus S,M,P Pharynx, larynx and viscera
XI Accessory M Two neck and upper back muscle
XII Hypoglossal M Tongue muscles
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PNS: SPINA L NERVES
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PNS: SPINA L NERVES
Dorsal roots: sensory
y Transmits sensory impulses from specific areas of body
called ´dermatomesµ to the dorsal horn ganglia.
y Somatic: from tendons, joints and body surfaces
y Visceral: from the internal organs
Ventral: motor
y Transmits impulses from the spinal cord to the body
y Somatic and visceral
Visceral: includes autonomic fibers that control cardiac
muscle and glandular secretions
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A UTONOMIC NERVOUS S YSTEM
Regulates theactivities of internalorgans
Maintains andrestores the internalhomeostasis
Two main divisions:y Sympathetic
y Parasympathetic(fight-or-flight)
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A UTONOMIC NERVOUS S YSTEMStructure/ Activity Parasympathetic
Effects
Sympathetic Effects
Pupil of Eye Constricts Dilate
Heart rate and force Decreases Increases
BP Decreases Increases
Bronchioles ConstrictsD
ilates
RR Decreased Increased
Peristaltic movement Increased Decreased
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