Nervous System Divisions
• Central Nervous System (CNS)
– Brain and Spinal Cord
• Peripheral Nervous System (PNS)
– All other nervous tissue throughout
the body
Central Nervous System (CNS)
• Nerve Tissue:
– White Matter or Gray Matter
The Brain
• One of the largest organ of the body
– Physical and mental activity
– Memory, emotion, thought, judgment,
reasoning and consciousness
• Four major structures
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Cerebrum
Cerebellum
Diencephalon
Brainstem
Cerebrum
• Sensory, perception and
interpretation, language, voluntary
movement, memory, emotional
behavior
Corpus Callosum
• Communicate right & left
Lobes of the Cerebrum
Cerebellum
• Functions involve movement,
equilibrium and balance
Diencephalon
• Thalamus:
– Receives all sensory stimuli except
olfactory
• Hypothalammus
– Regulates the autonomic nervous
system (ANS)
Brainstem
• 3 Structures: Midbrain, Medulla,
Pons
• Controls respirations, blood
pressure, and heart rate
Spinal Cord
• Ascending tracts: Sensory nerve
• Descending tracts: Motor nerve
Meninges
• 3 layers: Dura mater, arachnoid,
pia mater
Important Word Roots
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Cerebr/o
Crani/o
Encephal/o
Mening/o, meningi/o
Thalam/o
Peripheral Nervous System (PNS)
• All nervous tissue located outside
of the spinal column and brain
• Consists of 12 pairs of cranial
nerves
• 31 pairs of spinal nerves
• Subdivided: Somatic nervous
system(SNS) and Autonomic
Nervous System (ANS)
Somatic Nervous System (SNS)
• Nerve Fibers that
– Transmit sensory info to the brain,
spinal cord, and nerve fibers
– Transmits impulses from brain and
spinal cord to muscles
Autonomic Nervous System (ANS)
• Nerve Fibers that
– Control involuntary movement:
digestion, heart contractions,
vasoconstriction, regulation of
secretions by glands
– Subdivided:
• Sympathetic
• Parasympathetic
Sympathetic
• Fight or Flight
Parasympathetic
• Rest and Digest
Autonomic Nervous System
Cranial Nerves
• May be sensory, motor or mixed
– Sensory: ascending (afferent)
– Motor: descending (efferent)
12 Pairs of Cranial Nerves
I Olfactory: smell
II Optic: Vision
III Oculomotor: eyelid/eyeball motor
IV Trochlear: Turns eye
V Trigeminal: Chewing, face &
mouth touch, pain
• VI Abducens: Turns eye laterally
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12 Cranial Nerves
• VII Facial: facial expressions, tears,
saliva, taste
• VIII Vestibulocochlear: Hearing
equilibrium
• IX Glossopharyngeal: Taste,
senses carotid blood pressure
• X Vagus: senses aortic blood
pressure, slows heart, stimulates
digestive organs, taste
12 Cranial Nerves
• XI Spinal Accessory: controls
trapezius & sternocleidomastoid,
controls swallowing
• XII Hypoglossal: Controls Tongue
movements
Spinal Nerves
• 31 pairs
• Emerge from the intervertebral
spaces in the spinal column
• 2 points of attachment
– Anterior: contains motor fibers
– Posterior: contains sensory fibers
Spinal Nerves
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C1-C8 = Cervical Nerves
T1-T12 = Thoracic Nerves
L1-L5 = Lumbar Nerves
S1-S5 = Sacral Nerves
C0 = Coccygeal nerve
Medical Word Elements
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Kinesi/o
Myel/o
Neur/o
-Phasia
-plegia
Cerebrovascular Disease
• Functional abnormality caused by
disorders of the blood vessels of
the brain
• Stroke: Cerebr/o/vascul/ar accident
(CVA) (#3 & #1)
Cerebrovascular Disease
• Ischemic Stroke: narrowing of the
arteries of the brain
Cerebrovascular Disease
• Intra/cerebr/al Hem/o/rrhage: (#1/
#2) sudden rupture of an artery
within the brain
Cerebrovascular Disease
• Sub/arachnoid Hem/o/rrhage: (#2)
Blood is released into the space
surrounding the brain
Cerebrovascular Disease
• Transient Ischemic Attack (TIA):
mild CVA characterized by
blackouts, blurred vision or
dizziness
• F.A.S.T
Signs of Stroke
• Hemi/paresis: weakness in one half
of the body
• Hemi/plegia: paralysis in one half
of the body
• A/phasia: inability to speak
• A/taxia: lack of muscle coordination
Seizure Disorders
• Any medical condition
characterized by sudden changes
in behavior or consciousness as a
result of uncontrolled electrical
activity in the brain
Seizure Disorders
• Epi/lepsy: chronic or recurring
seizure disorders
Aura
• Premonitory awareness of an
approaching physical or mental
disorder, peculiar sensation that
precedes seizures
Convulsion
• Any sudden and violent contraction
of one or more muscles
Parkinson Disease
• Progressive neurological disorder
affecting the portion of the brain
responsible for controlling
movement
Parkinson’s Symptoms
• Brady/kinesia & Hypo/kinesia:
decreased speed of movement
• http://www.youtube.com/watch?v=
ECkPVTZlfP8
Multiple Sclerosis (MS)
• A progressive, degenerative
disease of the central nervous
system
Alzheimer Disease (AD)
• A progressive neurological disorder
that causes memory loss and
serious mental deterioration
Dementia
• Broad Term that refers to cognitive
deficit, including memory
impairment
Mental Illness
• Includes an array of psychological
disorders, syndromes, and
behavioral patterns that cause
alterations in mood, behavior, and
thinking
Mental Illness
• Psychosis: serious mental disorder
commonly characterized by
– False beliefs despite overwhelming
evidence to the contrary: delusions
– Hearing voices and seeing visions in
the absence of an actual stimuli:
Hallucinations
Mental Illness
• Neurosis: caused by an emotion
experienced in the past that
overwhelmingly interferes or affects
a present emotion
– Phobias: irrational fears
– Hysterias: exaggerated emotional
and reflexive behaviors
– Obsessive compulsive disorders:
uncontrolled ritualistic actions
Careers in Mental Illness
• Psych/iatr/ist: (#1) Medical
specialist in the diagnosis and
treatment of serious mental
disorders
• Clinical Psych/o/log/ist: (#2)
individuals trained in evaluating
human behavior, intelligence, and
personality
Medical Word Elements & Abbreviations
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-kinesia
-paresis
-taxia
CVA
TIA
PNS
SNS
ANS
Psych/o
R/O
CSF
Ataxia
• Lack of muscle coordination in the
execution of voluntary movement
Autism
• Developmental disorder
characterized by extreme
withdrawal and an abnormal
absorption in fantasy
Coma
• Abnormally deep unconsciousness
with absence of voluntary response
to stimuli
Closed Head Trauma
• Injury to the head in which the dura
mater remains intact and brain
tissue is not exposed
Concussion
• Injury to the brain, occasionally
with transient loss of
consciousness as a result of injury
or trauma to the head
• http://www.youtube.com/results?se
arch_query=NFL+helmet+to+helm
et
Dyslexia
• Inability to learn and process
written language despite adequate
intelligence, sensory ability and
exposure
Lethargy
• Abnormal inactivity or lack of
response to normal stimuli,
sluggish
Cerebral Palsy
• Type of paralysis that affects
movement and body position and,
sometimes, speech and learning
ability
Paralysis
• Loss of voluntary motion
– Hemiplegia: paralysis of one side of
the body
– Paraplegia: paralysis of both lower
limbs
– Quadriplegia: paralysis of both arms
and legs
Sciatica
• Severe pain in the leg
along the course of the
sciatic nerve felt at the
base of the spine, down
the thigh, and radiating
down the leg due to a
compressed nerve
Syncope
• Temporary loss of consciousness
due to the sudden decline of blood
flow to the brain (fainting)
Diagnostic & Therapeutic
• Lumbar Puncture: Needle puncture
of the spinal cavity to extract spinal
fluid for diagnostic purposes
• https://www.youtube.com/watch?v=
R2_0gOI8uV0
Diagnostic & Therapeutic
• Cerebrospinal Fluid (CSF)
Analysis: a series of lab test used
to diagnose disorders of the CNS,
including bacterial and viral
infections
Diagnostic & Therapeutic
• Angiography: Radiography of the
blood vessels after introduction of a
contrast medium
Diagnostic & Therapeutic
• Cryosurgery: Technique that
exposes abnormal tissue to
extreme cold to destroy it