Regulation and Integration of the Body
Te gray matter of the spinal cord forms from the alar and basal
plates. Fiber tracts form the outer white matter. Te neural crest
forms the sensory (dorsal root) ganglia.
Maternal and environmental factors may impair embryonic brain
development, and oxygen deprivation destroys brain cells. Severe
congenital brain disorders include cerebral palsy, anencephaly,
hydrocephalus, and spina biﬁda.
Premature babies have trouble regulating body temperature because
the hypothalamus is one of the last brain areas to mature prenatally.
Development of motor control indicates progressive myelination
and maturation of a child’s nervous system.
Brain growth ends in young adulthood. Neurons die throughout
life and most are not replaced; brain weight and volume decline
Healthy elders maintain nearly optimal intellectual function.
Disease—particularly cardiovascular disease—is the major cause
of declining mental function with age.
Poliomyelitis results from inﬂammation and destruction of the
ventral horn neurons by the poliovirus. Paralysis and muscle
Amyotrophic lateral sclerosis (ALS) results from destruction of
the ventral horn neurons and the pyramidal tracts. Te victim
eventually loses the ability to swallow, speak, and breathe. Death
generally occurs within ﬁve years.
Diagnostic Procedures for Assessing CNS
Diagnostic procedures used to assess neurological condition
and function range from routine reﬂex testing to sophisticated
techniques such as cerebral angiography, C± scans, MRI scans,
and PE± scans.
Developmental Aspects of the Central Nervous
Te CNS develops from the embryonic neural tube—the brain
from the rostral part and the spinal cord from the caudal part.
(Some questions have more than one correct answer. Select the best
answer or answers from the choices given.)
Te primary motor cortex, Broca’s area, and the premotor cortex
are located in which lobe?
Te innermost layer of the meninges, delicate and closely
apposed to the brain tissue, is the
Cerebrospinal ﬂuid is formed by
all of these.
A patient has suﬀered a cerebral hemorrhage that has caused
dysfunction of the precentral gyrus of his right cerebral cortex.
As a result,
he cannot voluntarily move his le² arm or leg,
he feels no sensation on the le² side of his body,
no sensation on his right side.
Choose the correct term from the key to respond to the
statements describing various brain areas.
Which of the following tracts convey vibration and other
speciﬁc sensations that can be precisely localized?
lateral spinothalamic tract,
Destruction of the ventral horn cells of the spinal cord results
in loss of
voluntary motor impulses,
all of these.
Fiber tracts that allow neurons within the same cerebral
hemisphere to communicate are
A number of brain structures are listed below. If an area is
primarily gray matter, write
in the answer blank; if mostly white
matter, respond with
corpus callosum and corona radiata
medial and lateral nuclear groups
cranial nerve nuclei
cingulate and precentral gyri
A professor unexpectedly blew a loud horn in his anatomy and
physiology class. Te students looked up, startled. Te reﬂexive
movements of their eyes were mediated by the
Identify the stage of sleep described by using choices from the
key. (Note that responses a–d refer to NREM sleep.)
the stage when blood pressure and heart rate reach
their lowest levels
indicated by movement of the eyes under the lids;
when nightmares are likely to occur
when the sleeper is very easily awakened; EEG shows
basal nuclei involved in ﬁne control of motor activities
region where there is a gross crossover of ﬁbers of
descending pyramidal tracts
control of temperature, autonomic nervous system
reﬂexes, hunger, and water balance
houses the substantia nigra and cerebral aqueduct
relay stations for visual and auditory stimuli input;
found in midbrain
houses vital centers for control of the heart, respiration,
and blood pressure
brain area through which all the sensory input is
relayed to get to the cerebral cortex
brain area most concerned with equilibrium, body
posture, and coordination of motor activity