Chapter 18

Nervous System

What is a Nervous System?
The nervous system carries out a wide variety of functions—from regulating heart rate and breathing, to allowing for consciousness and…
The Parasympathetic Nervous System
18.2: The Parasympathetic Nervous System
The parasympathetic nervous system is one of the major divisions of the autonomic nervous system (ANS)—also known as the visceral motor…
The Sympathetic Nervous System
18.3: The Sympathetic Nervous System
The sympathetic nervous system—one of the major divisions of the autonomic nervous system—is activated in times of stress. For example,…
The Blood-brain Barrier
18.4: The Blood-brain Barrier
The transport of nutrients and oxygen throughout the body is a critical process that depends on circulation and the passage of chemical components…
Neuron Structure
18.5: Neuron Structure
Neurons are the cells of the nervous system that generate and transmit electrical signals. These signals are sometimes directly communicated to other…
Glial Cells
18.6: Glial Cells
The nervous system is composed of two main types of cells: neurons and glial cells. Though neurons alone are responsible for sending and receiving…
Action Potentials
18.7: Action Potentials
The action potential is a specific “all-or-none” change in membrane potential—characterized by a quick spike in voltage—that…
The Resting Membrane Potential
18.8: The Resting Membrane Potential
The relative difference in electrical charge between the inside and outside of a cell membrane is called the membrane potential. It can be measured…
Long-term Potentiation
18.9: Long-term Potentiation
Long-term potentiation, or LTP, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in…
Long-term Depression
18.10: Long-term Depression
Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in…
Optogenetics
18.11: Optogenetics
Neural circuitry can also be investigated using optogenetics, in which neurons are modified to express light sensitive ion channels. When exposed to…
Developmental Biology: Immunostaining to Visualize Murine Enteric Nervous System Development
18.13: Developmental Biology: Immunostaining to Visualize Murine Enteric Nervous System Development
A functioning Enteric Nervous System controls motility, nutrient absorption, and blood flow and is formed from neural crest cells that colonize the…
Bioengineering: Three-dimensional Tissue Engineered Aligned Astrocyte Networks
18.14: Bioengineering: Three-dimensional Tissue Engineered Aligned Astrocyte Networks
The CNS has a limited capacity to counteract the loss of neurons and axonal pprjections from injury, stroke, or disease. In this article, living…
Medicine: A Drosophila In Vivo Injury Model for Studying Neuroregeneration
18.15: Medicine: A Drosophila In Vivo Injury Model for Studying Neuroregeneration
The inability of axons to regenerate after an injury or disease may lead to permanent disabilities in patients. This article presents a…