Download Chapter 10 THE NERVOUS SYSTEM

Chapter 10
THE NERVOUS
SYSTEM
OBJECTIVES
1.
2.
3.
4.
5.
Describe the functions and structures of the
nervous system.
Identify the major divisions of the nervous system
and describe the structures of each by location
and function.
Identify the medical specialists who treat disorders
of the nervous system.
Recognize, define, spell, and pronounce terms
related to the pathology and diagnostic and
treatment procedures of the nervous system.
Recognize, define, spell, and pronounce terms
related to the pathology and diagnostic and
treatment procedures of the mental health
disorders.
Key Word Parts
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Ambul/o
Cephal/o
Concuss/o
Contus/o
EchoEncephal/o
-esthesia
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Klept/o
Mening/o
Myel/o
Narc/o
Neur/i, neur/o
-phobia
Psych/o
Somn/o
Structures of
The Nervous
System
Coordinates and
controls all bodily
activities.
1. Brain
2. Spinal Cord
3. Nerves
4. Sensory Organs
Sensory Organs
• Receive external
stimulation and
transmit it to the
sensory neurons.
Three Parts of Nervous
System
• Central Nervous System (CNS)
– Brain and spinal cord
• Peripheral Nervous System (PNS)
– 12 pairs of cranial nerves
– 31 pairs of spinal nerves
• Autonomic Nervous System (ANS)
– Peripheral nerves and ganglia on either
side of the spinal cord
The Nerves
One or more bundles of neuron cells
(impulse carrying fibers) that connect the
brain and the spinal cord with other parts
of the body.
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Tract
Ganglion
Plexus
Innervation
Receptors
Stimulus
Impulse
Reflexes
Automatic, involuntary response to
some change.
– Heart rate
– Breathing
– Blood pressure
• Coughing, sneezing and reactions to
pain stimuli
Neuron
The basic part
Of the nervous
system
Types of Neurons
basic cell of the nervous system
• A-Afferent neurons
• Sensory neurons
• They emerge from the skin or sense organs and carry
impulses toward the brain and spinal cord.
• C-Connecting neurons
• Associative neurons
• They carry impulses from one neuron to another.
• E-Efferent neurons
• Motor neurons
• They carry impulses away from the brain and spinal
cord and toward the muscles and glands.
Neuron Parts
• Dendrites - receive
impulses and conduct
them to the cell body
• Axon – conducts
impulses away from
the nerve cell
• Terminal end fibers –
lead the nervous
impulse away from
the axon and toward
the synapse.
• Synapse – the space
between two neurons
• Neurotransmitter –
chemical messenger
that transmit
messages between
nerve cells
• 30 neurotransmitters
have been identified
• Neuroglia – glial cells,
supportive and
connective cells
(nerve cells)
Neurotransmitters and their
functions:
1. Acetylcholine – released at
some synapses in the
spinal cord and at
neuromuscular junctions, it
influences muscle actions.
2. Dopamine – released in the
brain thought to cause
some forms of psychosis
and abnormal movements
such as Parkinson’s
disease.
3. Endorphins – released
within the spinal cord;
inhibits pain impulses.
4. Serotonin – released in the
brain; has roles in sleep
and pleasure recognition.
The Central Nervous System
• Brain and the spinal cord are
protected by the:
– Meninges
• Dura mater
• Arachnoid membrane
• Pia mater
– Cerebrospinal fluid (CSF) – clear,
colorless, watery fluid
• Nourish, cool, and cushion the brain and
spinal cord from shock or injury
Three Layers of Meninges
(brain)
• Dura Mater
– Thick, tough, outermost
membrane
– Epidural space
– Subdural space
• Arachnoid Membrane
– Subarachnoid space
• Contains cerebrospinal
fluid
• Pia Mater
– Nearest to the brain and
spinal cord
– Connective tissue with rich
supply of blood vessels
Structures of the Brain
• Cerebrum- responsible for the
highest level of thought.
• Thalamus - monitors sensory
stimuli by suppressing some
and manifying others.
• Hypothalamus – controls vital
body functions.
• Cerebellum – coordinates
muscular activity for smooth
and steady movements.
• Pons – nerves cross over so
that one side of the brain
controls the opposite side of
the body.
• Medulla oblongata – controls
the basic vital functions of
life.
The Brainstem
• Midbrain
• Pons
– Nerves that control
the left side of the
body are found in
the right side and
vice versa
• Medulla Oblongata
– Lowest part of the
brainstem
The Cerebrum
• the largest and upper-most portion of the brain
• responsible for all thought, judgment, memory,
association, and discrimination
• Divided into left and right hemisphere
– Each hemisphere divided into four lobes
• Frontal lobe – motor functions
• Parietal lobe – receives and interprets nerve impulses
from the sensory receptors
• Occipital lobe – controls eyesight
• Temporal lobe – control the senses of hearing and
smell
Regulatory Functions of the
Hypothalamus
• Regulates heart rate, BP, respiratory rate,
and digestive tract activity.
• Regulate emotional responses and
behavior.
• Regulate body temperature.
• Regulate food intake by controlling hunger
sensations.
• Regulate water balance and thirst.
• Regulate sleep-wake cycles.
• Regulate endocrine system activity.
• Autonomic controls
the involuntary
actions of the body.
• Sympathetic prepares
the body for
emergency and
stressful situations by
increasing the
breathing rate, heart
rate, and blood flow to
muscles.
• Parasympathetic
returns the body to
normal after a
stressful response.
The
Spinal
Nerves
.
• 31 pairs of spinal
nerves extending
from the spinal
cord
• Receptors
– Eyes, ears, skin,
nose, and taste
buds
Reflex
– Autonomic,
involuntary
response to some
change
The Peripheral Nervous
System – 12 Cranial Nerves
I.
II.
III.
IV.
V.
VI.
Olfactory
Optic
Oculomotor
Trochlear
Trigeminal
Abducens
VII. Facial
VIII.Acoustic
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal
Medical Specialties Related
to the Nervous System
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Anesthesiologist
Anesthetist
Neurologist
Neurosurgeon
Psychiatrist
Psychologist
Pathology of the Nervous
System (see the text)
• Head and Meninges
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Cephalalgia
Migraine Headache
Encephalocele
Hydrocephalus
Meningocele
meningitis
Disorders of the Brain
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Alzheimer’s disease
Cognition
Encephalitis
Parkinson’s disease
Tetanus
Brain injuries
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Amnesia
Concussion
Cerebral contusion
Cranial hematoma
Altered States of
Consciousness
• Conscious
• Syncope
• Lethargy
• Stupor
• Coma
• Delirium
• Dementia
Strokes
• CVA
• Transient ischemic
attack (TIA)
• Ischemic stroke
• Cerebral
thrombosis
• Aphasia
• Hemorrhagic
stroke (bleed)
Sleep Disorders
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Insomnia
Narcolepsy
Somnambulism
Somnolence
Spinal Cord
• Myelitis
• Myelosis
• Multiple sclerosis
• Poliomyelitis
• Postpolio
• Radiculitis
(pinched nerve)
• Spinal cord
injuries
Nerves
• Amyotrophic lateral
sclerosis(Lou Gehrig’s
disease)
• Bell’s palsy
• Guillain-Barre
syndrome
• Peripheral neuropathy
• Tic douloureux
• Sciatica
High Spirited: Dr. William
Kuhlman now must
communicate with a pencil
and paper because of the
effects of ALS, or Lou Gehrig's
disease. Although Kuhlman's
mind is as sharp as ever, he
can't talk and barely has use
of his hands.
Abnormal
Sensations
• Causalgia
• Hyperesthesia
• Paresthesia
• Cerebral Palsy
Epilepsy
• Grand mal epilepsy
• Petit mal epilepsy
• Epileptic aura
Mental Health
• Developmental
Disorders
• Substance-Related
Disorders
• Schizophrenia and
other Psychotic
Disorders
• Mood Disorders
• Panic Disorders
• Anxiety Disorders
• Phobias
• Somatoform
Disorders
• Impulse-control
disorders
• Personality
Disorders
• Other conditions
Diagnostic Procedures of the
Nervous System
• Computed tomography or CAT scan
• MRI
• Echoencephalography
• Electroencephalography (EEG)
• Encephalography
• Myelography
• LOC
Treatment Procedures of the
Nervous System
• Medications to Treat
Mental Disorders
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Tranquilizers
Antidepressant
Antipsychotic
Psychotropic drugs
• Pain control
– Transcutaneous
electronic nerve
stimulation (TENS)
– Analgesic
– Nonnarcotic analgesics
– Narcotic analgesics
• Sedative and
Hypnotic meds
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Hypnotic
Barbiturate
Amobarbital
Phenobarbital
Anticonvulsant
• Anesthesia
– Topical, local,
regional
– Epidural
– Spinal
– General
Treatment…
• Brain and Head
– Electroshock
therapy (ECT)
– Lobectomy
– Thalamotomy
• Nerves
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Neurectomy
Neuroplasty
Neurorrhaphy
Neurotomy
Key Word Parts
•
•
•
•
•
•
•
Ambul/o
Cephal/o
Concuss/o
Contus/o
EchoEncephal/o
-esthesia
•
•
•
•
•
•
•
•
Klept/o
Mening/o
Myel/o
Narc/o
Neur/i, neur/o
-phobia
Psych/o
Somn/o
The Nervous System
THE END