This chapter expands on Chapter 4’s introduction to neurons
and other cells that make up the body’s nervous tissue (4.4).
Neurons produce nerve impulses in a process that depends
on the movement of substances across cell plasma mem-
branes (3.4, 3.10–3.11).
You’ll also get a fuller picture of how nervous system signals
make skeletal muscles contract (6.4).Key ConCepts
LinKs to earLier ConCepts
How Neurons Work
The operation of the nervous
system depends on the capacity
of neurons to produce electrical
signals and transmit them to other
cells. Sections 13.1–13.4Mind and body—your nervous system plays a
central role in managing your life. Together with hormones from the
endocrine system, it regulates all basic life-support activities. Your
brain also makes you who you are in other ways—thinking, feeling,
remembering the words to a favorite song. How can a small,
soft chunk of tissue—just 2 percent of your body weight—do
so much? Researchers today are discovering a wealth of details
about how the brain’s billions of neurons carry out their roles and
interact with the rest of the nervous system. We start our survey of
the nervous system by considering the structure and functioning
of neurons. We’ll then explore the major divisions of the nervous
system and see how the brain serves as the body’s master
control center.Top: TK; Second from top: © Cengage Learning; Second from bottom: Mark
Nielsen, Department of Biology, University of Utah; Bottom: © From Neuro
Via Clinical Research Program, Minneapolis Medical Center13 The Nervous System
Different parts of the nervous system
detect information, process it, and
then select or control muscles and
glands that carry out responses.
Sections 13.5 –13.6The Brain
The brain is a master controller that
receives, processes, stores, and
retrieves information. It also coordi-
nates responses by adjusting body
activities. Sections 13.7–13.1 0the nervous system
Disorders of the Nervous
System Sections 13.11–13.13coNNecTioNS:
The Nervous System in
Homeostasis S e c t i o n 13 .14239homeostasis preview
The nervous system provides much of the communication
required to monitor, adjust, and regulate body functions.Alexander Tsiaras/Science SourceCopyright 2016 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).