12
The Central Nervous System
The Brain
(pp. 429–452)
Embryonic Development (pp. 429–430)
Regions and Organization (p. 430)
Ventricles (p. 430)
Cerebral Hemispheres (pp. 430–441)
Diencephalon (pp. 441–443)
Brain Stem (pp. 443–447)
Cerebellum (pp. 447–449)
Functional Brain Systems (pp. 449–452)
Higher Mental Functions
(pp. 452–458)
Brain Wave Patterns and the EEG
(pp. 452–453)
Consciousness (pp. 453–454)
Sleep and Sleep-Wake Cycles (pp. 454–455)
Language (pp. 455–456)
Memory (pp. 456–458)
Protection of the Brain
(pp. 458–462)
Meninges (pp. 459–460)
Cerebrospinal Fluid (CSF) (pp. 460–462)
Blood Brain Barrier (p. 462)
Homeostatic Imbalances of the Brain
(pp. 462–464)
Traumatic Brain Injuries (pp. 462–463)
Cerebrovascular Accidents (CVAs)
(p. 463)
Degenerative Brain Disorders (pp. 463–464)
The Spinal Cord
(pp. 464–474)
Gross Anatomy and Protection
(pp. 464–466)
Spinal Cord Cross-Sectional Anatomy
(pp. 466–468)
Neuronal Pathways (pp. 468–473)
Spinal Cord Trauma and Disorders
(p. 474)
Diagnostic Procedures for Assessing
CNS Dysfunction
(pp. 474–475)
Developmental Aspects of the Central
Nervous System
(pp. 475–477)
428
I
nterconnecting and directing a dizzying number
of incoming and outgoing
calls, the central switchboard of a telephone system historically seemed an apt com-
parison for the
central nervous system (CNS)
—brain and spinal cord. Nowadays, many
people compare the CNS to a “cloud” of networked computers. Tese analogies may ex-
plain some workings of the spinal cord, but neither does justice to the fantastic complexity
of the human brain. Whether we view the brain as an evolved biological organ, an impres-
sive network of computers, or simply a miracle, it is one of the most amazing things known.
During the course of animal evolution,
cephalization
(sĕ
0
fah-lĭ-za
9
shun) has oc-
curred. Tat is, there has been an elaboration of the
rostral
(“toward the snout”), or an-
terior, portion of the CNS, along with an increase in the number of neurons in the head.
Tis phenomenon reaches its highest level in the human brain.
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