821
C h a p t e r
34
Organization and
Control of Neural
Function
Nervous Tissue Cells
Neurons
Neuroglial Cells
Neuroglial Cells of the Peripheral Nervous
System
Neuroglial Cells of the Central Nervous System
Metabolic Requirements of Nervous Tissue
Nerve Cell Communication
Action Potentials
Synaptic Transmission
Postsynaptic Potentials
Chemical Synaptic Transmission
Developmental Organization of the Nervous System
Embryonic Development
Segmental Organization
Cell Columns
Longitudinal Tracts
Spinal Cord and Brain
The Spinal Cord
Cross-Sectional Anatomy of the Spinal Cord
Protection of the Spinal Cord
Spinal Nerves
Spinal Reflexes
The Brain
Hindbrain
Midbrain
Forebrain
Meninges
Ventricular System and Cerebrospinal Fluid
Blood–Brain and Cerebrospinal Fluid–Brain
Barriers
The Autonomic Nervous System
Autonomic Efferent Pathways
Sympathetic Nervous System
Parasympathetic Nervous System
Central Integrative Pathways
Autonomic Neurotransmission
Acetylcholine and Cholinergic Receptors
Catecholamines and Adrenergic Receptors
T
Nervous System
10
U N I T
he nervous system, in coordination with the endo-
crine system, provides the means by which cell and
tissue functions are integrated into an independent, liv-
ing organism. It controls skeletal muscle movement and
helps to regulate cardiac and visceral smooth muscle
activity; it enables the reception, integration, and percep-
tion of sensory information; it provides the substratum
necessary for intelligence, anticipation, and judgment;
and it facilitates adjustment to an ever-changing exter-
nal environment.
NervousTissue Cells
Anatomically, the nervous system can be divided into
two basic components: the central and peripheral ner-
vous systems. The
central nervous system
(CNS) con-
sists of the brain and spinal cord, which are protected by
the skull and vertebral column. The
peripheral nervous
system
(PNS) includes the neurons outside the CNS (cra-
nial nerves and their ganglia, and spinal nerves and their
ganglia), which connect the brain and spinal cord with
peripheral structures. Inherent in the basic design of the
nervous system is the provision for the concentration of
computational and control functions in the CNS, with
the PNS relaying somatic and visceral sensory (afferent)
input to the CNS for processing and transmitting effer-
ent or motor output from the CNS to effector organs
throughout the body (Fig. 34-1).
