Transcript Ch 10MT and Ch 8-9 BS Nervous System

Chapter 10 Medical
Terminology
and
Chapters 8 – 9 Body
Structures:
THE NERVOUS SYSTEM
FUNCTIONS OF THE NERVOUS
SYSTEM
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Coordinates and controls
all bodily activities with the
brain at the center of
control
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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
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Tract: bundle or group of nerve fibers
located within the brain
Ascending: carry impulses toward brain
 Descending: carry away from brain
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Ganglion: knotlike mass or group of nerve
cells located outside the CNS
 Plexus: network of intersecting nerves and
blood or lymphatic vessels
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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 activated 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
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THE NEURONS – THE BASIC CELL
OF THE NERVOUS SYSTEM
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test
3 types described
according to function
(ACE)
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test
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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 PARTS
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Each neuron contains a cell
body, several dendrites, a
single axon, and terminal end
fibers
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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
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Chemical messengers
that transmits messages
between nerve cells
allowing a nerve impulse
to jump across the
synapse from one neuron
to another
www.patientcenters.com/autism/ news/neurology.html
MYELIN SHEATH
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PROTECTIVE
COVERING OVER
SOME NERVE CELLS
 Spinal Cord
 White Matter of the
Brain
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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.htm
training.seer.cancer.gov/ module anatomy/unit5...
MENINGES
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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 dura mater – within
surrounding bone walls – cushions Dura Mater
 Subdural space: below the dura membrane –
above the arachnoid membrane
CEREBRUM – cerebral: pertaining to cerebrum
or brain
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Largest/uppermost portion of the brain
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Responsible for all thought, judgment,
memory, association, and discrimination
Cerebral Cortex: made up of gray matter,
the outermost layer of the cerebrum
CEREBRAL LOBES
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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
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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
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CEREBELLUM
Second largest part of the brain
 Receives incoming messages regarding
movement within joints, muscle tone, and
positions of the body
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From here messages are distributed to
corresponding parts of the brain that controls
skeletal muscles
THE BRAINSTEM – connects cerebral
hemispheres with the spinal cord
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The Midbrain – extends from the lower surface of the cerebrum to
the pons –
 provides conduction pathways to and from higher and lower
centers
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The Pons – at the base of the brain
 Nerve cells cross from one side of the brain to control the
opposite side of the body (injuries)
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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 CSF
and meninges
 Grey Matter = internal
section
 White Matter = outer
portion of the spinal
cord
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www.bmb.psu.edu/.../bisci004a/ nerve/nerveb4.htm
THE PERIPHERAL NERVOUS
SYSTEM - PNS
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Consists of:
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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 names for the area
or function they serve
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Spinal nerves: 31 pairs
 Usually
named for the artery they accompany or
the body part they innervate
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Femoral nerve innervates muscles associated with the
femur
aer2.sbc.edu.hk/~bio/
THE AUTONOMIC NERVOUS
SYSTEM - ANS
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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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PATHOLOGY OF THE
 Head and Meninges
NERVOUS
SYSTEM
 Cephalalgia:
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headache
Migraine Headache
Encephalocele
Hydrocephalus:
increase amount of
CSF
Meningocele:
protrusion of
membranes through a
defect in the skull or
spinal column
Meningitis
www.enh.org/surgery/ 100128.asp
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 Hematomas:
collection of blood
trapped in the tissues of
the brain
BRAIN INJURIES
ALTERED STATES OF
CONSCIOUSNESS
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Conscious: alert
Syncope (SIN-koh-pee): also known as fainting, is the
brief loss of consciousness caused by the decreased
flow of blood to the brain.
Lethargy: lowered level of consciousness, listlessness,
drowsiness, and apathy
Coma
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
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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
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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
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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
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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
 Brain and Head
 Nerves
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