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Chapter 10
Medical
Terminology
and
Chapters 8 – 9
Body Structures:
THE NERVOUS
SYSTEM
FUNCTIONS OF THE
NERVOUS SYSTEM

Coordinates and
controls all bodily
activities with the
brain at the center
of control

When the brain
ceases function,
the body dies
STRUCTURES OF THE
NERVOUS SYSTEM

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BRAIN
SPINAL CORD
NERVES
SENSORY
ORGANS
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CNS (central)
PNS
(peripheral)
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12 pairs cranial
nerves
31 pairs of
spinal nerves
ANS
(autonomic)
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Peripheral
nerves
Ganglia on
either side of
the spinal cord
NERVES – one or bundles of
neuron cells (carrying impulses)
connecting brain and spinal cord with
body

Tract: bundle or group of nerve
fibers located within the brain
Ascending: carry impulses
toward brain
 Descending: carry impulses
away from brain

Ganglion: knotlike mass or
group of nerve cells located
outside the CNS
 Plexus: network of intersecting
nerves and blood or lymphatic
vessels

dtc.pima.edu/biology/160alpha/ lesson9/lesson9h.ht

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Innervation: supply of nerves to
body part, stimulation of a body
part through action of nerves
Receptors: sites in sensory organs
that receive external stimulation
 Send stimulus through the
sensory neurons to the brain for
interpretation
 Stimulus: excites or activates
nerve causing an impulse
 Impulse: wave of excitation
transmitted through nerve fibers
and neurons
REFLEXES
Automatic, involuntary
response to change,
inside/outside body
 Maintenance of heart rate,
breathing rate, and blood
pressure = reflex actions
 Coughing, sneezing, and
reactions to painful stimuli are
also reflex actions

THE NEURONS – THE
BASIC CELL OF THE
NERVOUS SYSTEM

3 types
described
according to
function (ACE)

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Afferent:
sensory,
emerge from
skin, carry
impulses
toward brain
Connecting:
carry impulses
from one
neuron to
another
Efferent: carry
impulses away
from brain
toward
muscles and
glands

NEURON
Each neuron contains
PARTS
a cell body, several
dendrites, a single
axon, and terminal
end fibers


Dendrites: receive
impulses and conduct
them to the cell body
Axon: extends away
from the cell body,
conducts impulses
away from the nerve
cell

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Some but not all
axons protected by
myelin
Terminal end fibers:
lead the nervous
impulse away from the
axon and toward the
synapse
Synapse: space between two
neurons or between a neuron
and receptor organ
dendrites
Synaptic pathway
axon
terminal end
fibers
NEUROTRANSMITTERS

Chemical
messengers that
transmit
messages
between nerve
cells allowing a
nerve impulse to
jump across the
synapse from one
neuron to another
www.patientcenters.com/autism/ news/neurology.
MYELIN SHEATH

PROTECTIVE
COVERING
OVER SOME
NERVE CELLS
 Spinal Cord
 White Matter of
the Brain


White color of
myelinated
nerve fibers
Most
Peripheral
Nerves
Gray Matter: non-myelinated
nerves of the brain and
spinal cord
nucleus
dendrite
axon
Myelin sheath
Nodes of
Ranvier
Cell body
THE
CENTRAL
NERVOUS
SYSTEM

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Meninges
 Dura Mater
 Arachnoid
Membrane
 Pia Mater
Cerebrospinal Fluid
The Cerebrum
 Cerebral
Hemispheres
 Lobes
 Ventricles
The Thalamus
 The
Hypothalamus
The Cerebellum
The Brainstem
 The Midbrain
 The Pons
 The Medulla
Oblongata
The Spinal Cord
www.lougehrigsdisease.net/ als_pages/neurolog.h
training.seer.cancer.gov/ module_anatomy/unit5...
MENINGES

3 Layers of connective tissue that
enclose brain and spinal cord
 Dura Mater – outermost membrane
 Arachnoid Membrane – second
layer, loosely attached to allow flow
of fluid between layers
 Pia Mater – third layer, located
closest to brain and spinal cord, rich
in supply of blood vessels
 Subarachnoid space: below
arachnoid membrane, above pia
mater – contains cerebrospinal
fluid
 Epidural space: above the
duramater – within surrounding
bone walls – cushions Dura Mater
 Subdural space: below the dura
membrane – above the arachnoid
membrane
CEREBRUM – cerebral:
pertaining to cerebrum or brain

Largest/uppermost portion of
the brain


Responsible for all thought,
judgment, memory, association,
and discrimination
Cerebral Cortex: made up of
gray matter, the outermost
layer of the cerebrum
CEREBRAL LOBES

Frontal – controls motor functions

Parietal – receives and interprets
nerve impulses from the sensory
receptors

Occipital – controls eyesight

Temporal Lobe –
controls senses of hearing and smell
THALAMUS – produces
sensations by relaying impulses
to/from the cerebral cortex and the
sense organs of the body

Hypothalamus: 7 regulatory
functions
Controls heart rate, blood
pressure, respiratory rate, and
digestive tract activity by
regulating autonomic nervous
system
 Regulates emotional responses
and behavior
 Regulates body temperature
 Regulates food intake by
controlling hunger sensations
 Regulates water balance and
thirst
 Regulates sleep-wake cycles
 Regulates endocrine system
activity

CEREBELLUM
Second largest part of the
brain
 Receives incoming messages
regarding movement within
joints, muscle tone, and
positions of the body


From here messages are
distributed to corresponding
parts of the brain that control
skeletal muscles
THE BRAINSTEM – connects
cerebral hemispheres with the spinal cord

The Midbrain – extends from the lower surface of
the cerebrum to the pons –
 provides conduction pathways to and from
higher and lower centers

The Pons – at the base of the brain
 Nerve cells cross from one side of the brain to
control the oppositie side of the body (injuries)

The Medulla Oblongata – located at the lowest
part of the brainstem
 Controls basic life functions including the
muscles of respiration, heart rate, and blood
pressure
THE SPINAL CORD –
pathway for impulses going to and from the
brain
Contains all the
nerves that
affect the limbs
and lower part
of the body
 Protected by
Cerebral Spinal
Fluid and
meninges
 Grey Matter =
internal section
 White Matter =
outer portion of
the spinal cord

www.bmb.psu.edu/.../bisci004a/ nerve/nerveb4.htm
THE PERIPHERAL
NERVOUS SYSTEM PNS

Consists of:

Cranial nerves: 12 pairs
originating from under the brain
 Each
nerve of a pair serves half the
body
 Both nerves in a pair are identical
in function
 Identified by Roman numerals
named for the area or function they
serve

Spinal nerves: 31 pairs
 Usually
named for the artery they
accompany or the body part they
innervate

Femoral nerve innervates muscles
associated with the femur
aer2.sbc.edu.hk/~bio/
THE AUTONOMIC
NERVOUS SYSTEM ANS


Controls involuntary actions of the body
2 divisions: function to maintain
homeostasis
 Sympathetic: prepares body for
emergency and stressful situations
 Parasympathetic: returns body to
normal after a stressful response
MEDICAL SPECIALTIES
RELATED TO THE
NERVOUS SYSTEM
Anesthesiologist
 Neurologist
 Neurosurgeon
 Psychiatrist
 Psychologist
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Head and
Meninges
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PATHOLOGY OF
THE NERVOUS
SYSTEM
Cephalalgia:
headache
Migraine
Headache
Encephalocele
Hydrocephalus
: increased
amount of CSF
Meningocele:
protrusion of
membranes
through a
defect in the
skull or spinal
column
Meningitis
www.enh.org/surgery/ 10012
DISORDERS OF THE BRAIN
Alzheimer’s disease:
associated with degenerative
changes in the brain structures
 Cognition: mental activities
associated with thinking,
learning, and memory
 Encephalitis
 Parkinson’s disease
 Tetanus
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Amnesia:
disturbance in the
memory marked by
total or partial
inability to recall past
experiences – cause
BI, illness, or
psychological
disturbances
Concussion: violent
shaking up or jarring
of the brain
Cerebral Contusion:
bruising of brain
tissue as result of BI
Cranial Hepatomas:
collection of blood
trapped in the
tissues of the brain
BRAIN
INJURIES
ALTERED STATES OF
CONSCIOUSNESS
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Conscious: alert
Syncope: fainting
Lethargy: lowered level of
consciousness, listlessness,
drowsiness, and apathy
Coma : loss of consciousness
Delirium: associated with high
fever, sudden onset where patient
is confused, disoriented, and
unable to think clearly
Dementia: slow, progressive
decline in mental abilities including
memory, thinking, judgment, and
the ability to pay attention
STROKES – (CVA) damage
to the brain that occurs when blood
flow is disrupted due to vessel
blockage or rupture

Ischemic Attacks
TIA: temporary interruption in
blood supply to brain: weakness,
dizziness, or loss of balance
 Ischemic stroke: blood flow is
blocked, affecting the cerebrum
and damaging the controls of
movement, language, and
senses
 Aphasia: inability to speak, write,
or comprehend written or spoken
word


Hemorrhagic Stroke – bleed –
leak or rupture of blood vessel
in brain
www.providence.org/swsa/Services/ e60Neurology.htm
www.providence.org/swsa/Services/ e60Neurology.htm
SLEEP DISORDERS

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Insomnia:
abnormal
inability to
sleep
Narcolepsy:
recurrent
uncontrollable
seizures of
drowsiness
and sleep
www.cartoonstock.com/.../ napping_at_the_desk.asp
www.tipsofallsorts.com/ narcolepsy.html
SPINAL CORD
Myelitis: inflammation of the
spinal cord
 Myelosis: tumor of spinal cord
 Multiple sclerosis
 Poliomyelitis
 Post polio syndrome
 Radiculitis: pinched nerve,
inflammation of root of spinal
nerve
 Spinal cord injuries

CONVULSIONS AND
SEIZURES – sudden, violent,
involuntary contraction of a group of
muscles caused by a disturbance in
brain function
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Generalized tonic-clonic seizure:
Tonic convulsion: continuous
muscular contraction resulting in
rigidity and violent spasms
Clonic convulsion: alternate
contraction and relaxation of
muscles resulting in jerking
movements of the face, trunk, or
extremities
Localized seizure: partial
EPILEPSY
Grand Mal Epilepsy: most
severe form
 Petit Mal Epilepsy: milder form,
sudden, temporary loss of
consciousness, lasting only a
few seconds, they may not
involve convulsive movements,
and may not be noticed
 Epileptic aura: experienced just
before seizure, light or smell
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MENTAL HEALTH
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Developmental Disorders
Substance-Abuse Disorders
Schizophrenia and Other Psychotic
Disorders
Mood Disorders
Panic Disorders
Anxiety Disorders
Phobias
Somatoform Disorders
Impulse-Control Disorders
Personality Disorders
DIAGNOSTIC
PROCEDURES OF THE
NERVOUS SYSTEM
CT – CAT Scan
 Echoencephalography
 Electroencephalography
 Encephalography
 Myelography: radiographic
study of spinal cord
 LOC: level of consciousness

Echo
encephalography
myelography
Electrical
encephalography
Ct scan
TREATMENT
PROCEDURES OF THE
NERVOUS SYSTEM
Medications to Treat Mental
Disorders
 Pain Control
 Sedative and Hypnotic
Medications
 Anesthesia
