Download Ch. 10 Neurology

Neurology – Ch. 10
The medical specialty that studies the anatomy
and physiology of the nervous system and uses
diagnostic tests, medical and surgical
procedures, and drugs to treat nervous system
diseases.
Nervous System
-Found in every part of the
body from the head to the
tips of the fingers and toes.
-Divided into central
nervous system (CNS) and
peripheral nervous system
(PNS).
-CNS contains brain and
spinal cord.
-PNS contains cranial
nerves, spinal nerves, and
nerves that travel
throughout the body.
Figure 10-1 Nervous system
Figure 10-2 Divisions of the nervous system
Types of Neural Tissue:
-Neural tissue is made up of two categories of cells:
neurons and neuroglia.
-A neuron, an individual nerve cell, it is the
functional unit of the nervous system.
-Nerves are bundles of individual nerve cells
(neurons).
-Neuroglia perform specialized tasks to help neurons
do their work.
Physiology of a Neuron and
Neurotransmitters
Neuron structure:
1. Dendrites
2. Cell body
3. Axon
Dendrites
-Multiple branching
structures at the beginning
of the neuron
Cell body
-Contains the nucleus,
which directs cellular
activities
-Contains cytoplasm;
structures in the cytoplasm
produce neurotransmitters
as well as energy for the
neuron
Axons
-An elongated extension of
cytoplasm at the end of
the neuron.
-Larger axons are covered
by a fatty, white insulating
layer of myelin that
dramatically increases the
speed at which an
electrical impulse can
travel along the axon.
(Myelin sheath)
-Neurotransmitters
Figure 10-10 Neuron
Table 10-3 Neurotransmitters
Meninges:
The brain is surrounded by
the meninges, three
separate membrane layers.
1. Dura mater (outermost,
tough, fibrous layer that
protects the brain).
2. Arachnoid (subarachnoid
space is filled with CSF).
3. Pia mater (innermost
layer; thin, delicate
membrane next to the brain
that contains many small
blood vessels).
Figure 10-7 Meninges
Anatomy of the Central Nervous System
Brain
-Located within the bony cranium
-Fills the cranial cavity
-Consists of the cerebrum (and its lobes), thalamus,
hypothalamus, ventricles, brain-stem, and
cerebellum
-Surrounded by the meninges, three layers of
membranes
-Largest part of the brain is the cerebrum
Figure 10-3 Lobes of the cerebrum
Figure 10-4 Midline cut section of the brain
Reprinted from McMinn’s Color Atlas of Human Anatomy, 2/E. McMinn, Hutchings, Human Anatomy,
19,46,66,71.78,127,137,237,238. Copyright 2002, with permission from Elsevier.
Figure 10-5 Posterior half of the brain
Reprinted from McMinn’s Color Atlas of Human Anatomy, 2/E. McMinn, Hutchings, Human Anatomy,
19,46,66,71.78,127,137,237,238. Copyright 2002, with permission from Elsevier.
Structures of the Brain:
Cerebrum
-The surface of the cerebrum
has elevated folds (gyri) and
narrow grooves (sulci).
-The cerebral cortex, or gray
matter, is the outermost layer of
the cerebrum.
-Beneath the gray matter, the
white matter of the cerebrum is
composed of the axons of
neurons.
-Most of these axons are
covered by a fatty, white
insulating layer of myelin.
Cerebrum
-A deep fissure divides the
cerebrum into right and
left halves; each half is a
hemisphere.
-The corpus callosum
connects the two
hemispheres. It is an arch
of nerves that allows the
two hemispheres to
communicate with each
other and coordinate their
activities.
Right Hemisphere of the
Cerebrum:
-Recognizes faces,
patterns, and threedimensional structures
-Analyzes the emotional
content of words but not
the actual words
Left Hemisphere of the
Cerebrum
-Performs mathematical
and logical reasoning and
problem-solving
-Coordinates the recall of
memories
-Contains the speech
center and is important in
language skills
Cerebrum
-Each hemisphere of the
cerebrum is divided into
sections or lobes.
-Each lobe has the same
name as the cranial bone
that is above it.
Frontal Lobe of the
Cerebrum:
-Thought and intelligence.
-Predicts future events and
the benefits or
consequences of actions.
-Coordinates and analyzes
information coming from
other lobes of the
cerebrum.
-Exerts conscious,
voluntary control over the
skeletal muscles.
-Speech
Temporal Lobe of the
Cerebrum
-Analyzes sensory
information about hearing
-Analyzes sensory
information about smells
Occipital Lobe of the
Cerebrum
-Analyzes sensory
information about vision
Parietal Lobe of the
Cerebrum
-analyzes sensory info
about touch, temperature,
vibration, pain, and taste.
Cerebellum
-analyzes sensory info
about muscles,
coordination, and balance.
Thalamus:
-Acts as a relay station,
receiving sensory
information from the
cranial nerves and the
spinal nerves, and sending
it to the midbrain and
cerebrum.
-Part of the limbic system
that deals with emotions.
Hypothalamus:
-Connects to the pituitary gland;
functions are part of both the
endocrine and nervous systems.
-Coordinates the activities of the
pons and medulla oblongata
that control the heart rate,
blood pressure, and respiratory
rate.
-Regulates body temperature,
hunger and thirst, and the
circadian (24-hour) rhythm of
the body.
-Plays a role in emotions and the
sexual drive.
Ventricles:
-Four interconnected
cavities within the brain.
-Lined with ependymal
cells that produce
cerebrospinal fluid (CSF), a
clear, colorless fluid that
cushions and protects the
brain and contains glucose
and other nutrients.
Brain Stem:
-Composed of the
midbrain, the pons, and
the medulla oblongata.
-Midbrain coordinates
immediate reflex
responses, maintains
muscle tone and position
of extremities, contains the
substantia nigra that
produces dopamine.
Brain Stem:
-Pons is a relay station that
links the spinal cord to the
midbrain, hypothalamus,
thalamus, and cerebrum.
-Medulla oblongata
contains centers that set
the respiratory rate and
control the heart rate.
Spinal Cord
-part of the central
nervous system.
-located in the spinal cavity
-Protected by the
vertebrae
Figure 10-8 Spinal cord
Peripheral Nervous System
Cranial Nerves
-Part of the peripheral nervous system
-12 pairs
-Sensory and/or Motor neurons
Table 10-1 Cranial Nerves
Table 10-1 (cont’d) Cranial Nerves
Table 10-1 (cont’d) Cranial Nerves
Table 10-1 (cont’d) Cranial Nerves
Table 10-1 (cont’d) Cranial Nerves
Table 10-1 (cont’d) Cranial Nerves
Table 10-1 (cont’d) Cranial Nerves
Peripheral Nervous System
Spinal Nerves
-Part of the peripheral
nervous system.
-There are 31 pairs that
originate at regular
intervals along the spinal
cord.
-Each spinal nerve has two
different groups of nerve
roots that connect it to the
spinal cord: dorsal nerve
roots and ventral nerve
roots.
-Dorsal nerve roots receive
sensory information from
the skin, muscles, and
joints; afferent nerve root.
-Ventral nerve roots carry
motor commands from the
spinal cord to skeletal
muscles and involuntary
smooth muscles; efferent
nerve root.
Peripheral Nervous System
Reflex:
-A reflex is a rapid, involuntary muscle reaction
that is controlled by the spinal cord.
-The spinal cord reacts immediately to certain
types of sensory information, such as sudden
pain.
Figure 10-9 Spinal nerves
Peripheral Nervous System
Somatic Nervous System:
-Controls the voluntary
movements of skeletal
muscles
-Motor commands are the
result of conscious
thoughts in the brain.
Autonomic Nervous
System:
-Controls the involuntary
contractions of cardiac
muscle in the heart, as well
as smooth muscles within
organs, glands, and other
structures
-Can be broken down into
two divisions:
• Parasympathetic division
• Sympathetic division
Peripheral Nervous System
Parasympathetic Division
-Active during “rest and digest”
activities
-Decreases heart rate, blood
pressure, and metabolic rate
-Changes the diameter of the pupils
-Increases peristalsis in the GI tract
-Causes secretion of saliva, digestive
enzymes, and insulin
-Prepares the body for sexual
activity
-Contracts the bladder for urination
Sympathetic Division
-Active when body is active or
exercising
-Increases mental alertness
-Dilates pupils to optimize vision
-Increases heart rate and metabolic
rate
-Raises blood pressure
-Increases air flow to the lungs
-Increases respiratory rate
-Causes release of stored glucose to
meet increased energy needs
-Prepares the body for “fight or
flight”
End of Quiz #1 Material.
Autonomic Nervous System
Animation
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Diseases and Conditions: Brain
Amnesia
Anencephaly
Aphasia
Arteriovenous malformation
(AVM)
Brain tumor
Cephalalgia
Cerebral palsy (CP)
Cerebrovascular accident (CVA)
Coma
Concussion
Dementia
Down syndrome
Dyslexia
Encephalitis
Epilepsy
Hematoma
Huntington’s chorea
Hydrocephalus
Meningitis
Migraine headache
Narcolepsy
Parkinson’s disease
Syncope
Table 10-4 Types of Brain Tumors
Table 10-4 (cont’d) Types of Brain Tumors
Figure 10-11 Glioma
Simon Fraser/Photo Researchers, Inc.
Figure 10-12 Cerebrovascular accident
Aneurysms Video
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Figure 10-15 PET scan of a normal brain
Science Photo Library/Custom Medical Stock Photo, Inc.
Figure 10-16 PET scan of the brain of a patient with Alzheimer’s disease
Science Photo Library/Custom Medical Stock Photo, Inc.
Figure 10-18 Dyslexia
Will & Deni McIntyre/Photo Researchers, Inc.
Table 10-5 Seizures
Table 10-5 (cont’d) Seizures
Seizures Animation
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Figure 10-20 Subdural hematoma
Figure 10-21 Hydrocephalus
Figure 10-22 Parkinson’s disease
Diseases and Conditions
Spinal Cord:
-Neural tube defect
-Radiculopathy
-Spinal cord injury (SCI)
Figure 10-23 Meningocele
Figure 10-24 Radiculopathy
Figure 10-25 Spinal cord injury
Diseases and Conditions
Nerves:
-Amyotrophic lateral
sclerosis (ALS)
-Anesthesia
-Bell’s palsy
-Carpal tunnel syndrome
(CTS)
-Guillain-Barré syndrome
-Hyperesthesia
-Multiple sclerosis (MS)
-Neuralgia
-Neuritis
-Neurofibromatosis
-Neuroma
-Neuropathy
-Paresthesia
Figure 10-26 Bell’s palsy
Multiple Sclerosis Animation
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Laboratory and Diagnostic Procedures
Laboratory Tests:
-Alpha fetoprotein (AFP)
-Cerebrospinal fluid (CFS) examination
Laboratory and Diagnostic Procedures
Radiologic and Nuclear Medicine Procedures:
-Cerebral angiography
-Computed axial tomography (CAT, CT)
-Doppler ultrasonography
-Magnetic resonance imaging (MRI)
-Myelography
-Positron emission tomography (PET) scan
-Skull x-ray
Figure 10-28 Arteriogram
Corbis RF
PET Scans Animation
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Laboratory and Diagnostic Procedures
Other Diagnostic Tests:
-Electroencephalography (EEG)
-Evoked potential testing
-Nerve conduction study
-Polysomnography
Figure 10-29 Electroencephalography (EEG)
Phanie/Photo Researchers, Inc.
Medical and Surgical Procedures
Medical Procedures:
-Babinski’s sign
-Glasgow Coma Scale (GCS)
-Lumbar puncture (LP)
-Mini mental status examination (MMSE)
-Neurologic examination
-Spinal traction
-Transcutaneous electrical nerve stimulation (TENS)
unit
Figure 10-30 Positive Babinski’s sign
Pearson Education/PH College
Figure 10-31 Lumbar puncture
(b) Peres/Custom Medical Stock Photo, Inc.
Figure 10-32 Spinal traction with tongs
Vanstrum/Custom Medical Stock Photo, Inc.
Medical and Surgical Procedures
Surgical Procedures:
-Biopsy
-Carotid endarterectomy
-Craniotomy
-Diskectomy
-Laminectomy
-Stereotactic neurosurgery
-Ventriculoperitoneal shunt
Abbreviations