Autonomic Nerve Fibers

All of the nerve fibers of the autonomic nervous system are efferent, or motor, fibers. In the motor pathways of the somatic nervous system, a single neuron typically links the central nervous system and a skeletal muscle. In the auto-nomic system, motor pathways include two neurons, as figure 11.36 shows. The cell body of one neuron is located in the brain or spinal cord. Its axon, the preganglionic (pre"gang-gle-on'ik) fiber, leaves the CNS and synapses with one or more nerve fibers whose cell bodies are housed within an autonomic ganglion. The axon of such a second neuron is called a postganglionic (post"gang-gle-on'ik) fiber, and it extends to a visceral effector.

Essentials of Human Physiology

Essentials of Human Physiology

This ebook provides an introductory explanation of the workings of the human body, with an effort to draw connections between the body systems and explain their interdependencies. A framework for the book is homeostasis and how the body maintains balance within each system. This is intended as a first introduction to physiology for a college-level course.

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