Nervous tissue is a complex organization of several cell types.

In addition to various kinds of neurons, it contains

• Glial cells of several different varieties and
• Blood vessels and
• Connective tissue coverings.

The neurons are specialized to conduct impulses. The glial cells are involved in the nutrition and formation of sheaths around the neurons and play an important role in inflammatory reactions.

Note: The purpose of this exercise is to familiarize you with the cellular and histological features of nervous tissue. It is not necessary for you to know and identify distinct functional regions within the various structures of the central nervous system. This will be covered in the Neuroscience course next semester.

Learning Objectives:

• Understand that nervous tissues contain both neurons and supporting cells (neuroglial cells).
• Understand the nature of neuronal cells bodies, axons, and dendrites and their functional significance.
• Understand that materials move in axons through retrograde and anterograde transport and the importance of this movement for axon growth/regeneration.
• Understand the different types of neurons based on structure and connectivity: bipolar, (pseudo)unipolar, and multipolar.
• Know the connective tissue coverings in peripheral nerves and their roles.
• Understand the structure and function of myelin sheaths of axons in both the CNS and PNS, how myelin is produced and maintained, and the difference between myelinated and unmyelinated fibers in peripheral nerves.
• Understand the major features of synapses.
• Understand the histological structure of peripheral ganglia.
• Understand the roles of endothelial cells and astrocytes in the blood-brain barrier.
• Understand the interrelationship among ependymal cells, choroid plexus, and cerebrospinal fluid (CSF).
• Understand the structure and functions of the meninges and their relationship to the CNS.

Slides and Micrographs