482
UNIT 3
Regulation and Integration of the Body
physician suspects meningitis and performs a lumbar tap. Using
your knowledge of neuroanatomy, explain into which space and
at what level of the vertebral column the needle will be inserted to
perform this test. Which fluid is being obtained and why?
7.
Five-year-old Amy wakes her parents up at 3 ±M crying and
complaining of a sore neck, severe headache, and feeling sick to
her stomach. She has a temperature of 40°C (104°F) and hides
her eyes, saying that the lights are too bright. Te emergency
Related Clinical Terms
Autism
A complex developmental neurological disorder, typically
appearing in the first three years of life, characterized by
difficulty in communicating, forming relationships with others,
and responding appropriately to the environment. A wide
variety of mutations in functionally related genes can give rise to
autism and its related disorders. Occurs in about two per 1000
people, and early behavioral intervention is beneficial.
Cordotomy
(kor-dot
9
o-me) A procedure in which a tract in
the spinal cord is severed surgically; usually done to relieve
unremitting pain.
Dyslexia
A learning disability in 5 to 15% of the population that
specifically affects the ability of otherwise intelligent people
to read. Tis deficit in visual symbol and language processing
is thought to result from errors arising in one hemisphere.
Several genes that predispose children to dyslexia have been
identified, but dyslexia can also be acquired by brain injury or
degeneration.
Encephalopathy
(en-sef
0
ah-lop
9
ah-the;
enceph
5
brain;
path
5
disease) Any disease or disorder of the brain.
Hypersomnia
(
hyper
5
excess;
somnus
5
sleep) A condition in
which affected individuals sleep as much as 15 hours daily.
Microcephaly
(mi
0
kro-sef
9
ah-le;
micro
5
small) Congenital
condition involving the formation of a small brain, as evidenced
by reduced skull size; most microcephalic children are mentally
retarded.
Myelitis
(mi
0
ĕ-li
9
tis;
myel
5
spinal cord;
itis
5
inflammation)
Inflammation of the spinal cord.
Myelogram
(
gram
5
recording) X ray of the spinal cord a²er
injection of a contrast medium.
Myoclonus
(mi
0
o-klo
9
nus;
myo
5
muscle;
clon
5
violent motion,
tumult) Sudden contraction of a muscle or muscle part, usually
involving muscles of the limbs. ³yoclonal jerks can occur in
normal individuals as they are falling asleep; others may be due
to diseases of the reticular formation or cerebellum.
Neuroses
(nu-ro
9
sēs) A less debilitating class of mental illness;
examples include severe anxiety (panic attacks), phobias
(irrational fears), and obsessive-compulsive behaviors (e.g.,
washing one’s hands every few minutes). However, the affected
individual retains contact with reality.
Psychoses
(si-ko
9
sēs) A class of severe mental illness in which
affected individuals lose touch with reality and exhibit bizarre
behaviors; the legal word for psychotic behavior is insanity.
Psychoses include schizophrenia (skit-so-fre
9
ne-ah), bipolar
disorder, and some forms of depression.
AT T H E C L I N I C
Margaret Bryans, a 39-year-old
female, was a passenger on the bus
that crashed on Route 91. When
paramedics arrived on the scene, she
was unconscious, with cuts on her arms, face, and scalp. She
regained consciousness en route to the hospital and appeared
agitated and combative. Paramedics observed that she had a right
hemiparesis (muscle weakness), with a near complete paresis of
her right upper extremity and a partial paresis of the right lower
extremity. A head CT scan revealed an acute subdural hematoma
and an extensive subarachnoid hemorrhage. Doctors noted that
she was able to follow commands from medical personnel. With
difficulty, she could speak haltingly, using only simple words.
Surgery to remove large clots from the subarachnoid space was
performed immediately. Two weeks after the surgery, she showed
significant improvement in her speech and motor function.
1.
The adult brain can be broken down into four functional
regions (see Table 12.1). Based on the observed signs in this
case, which of these four brain regions is involved? What
evidence did you use to determine this?
2.
Which side of the brain is involved in Mrs. Bryans’s injury? What
evidence did you use to determine this?
3.
What specific parts of the region of the brain you identified in
question 1 are being affected by the injury to cause the muscle
weakness and language problems?
4.
What are the three membranes that make up the meninges?
Describe their positions relative to the brain.
5.
Relative to the meninges, describe the location of the bleeding
revealed on the CT scan.
(Answers in Appendix H)
Case Study
Central Nervous System
12
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