Skip to main content
Medicine LibreTexts

10: Nervous Tissue

  • Page ID
    12530
  • Nervous tissue is composed of two types of cells, neurons and glial cells. Neurons are the primary type of cell that most anyone associates with the nervous system. They are responsible for the computation and communication that the nervous system provides. They are electrically active and release chemical signals to target cells. Glial cells, or glia, are known to play a supporting role for nervous tissue. Ongoing research pursues an expanded role that glial cells might play in signaling, but neurons are still considered the basis of this function. Neurons are important, but without glial support they would not be able to perform their function.

    Neurons

    Neurons are the cells considered to be the basis of nervous tissue. They are responsible for the electrical signals that communicate information about sensations, and that produce movements in response to those stimuli, along with inducing thought processes within the brain. An important part of the function of neurons is in their structure, or shape. The three- dimensional shape of these cells makes the immense numbers of connections within the nervous system possible.

    image

    Figure 10.1 Parts of a Neuron The major parts of the neuron are labeled on a multipolar neuron from the CNS.

    Where the axon emerges from the cell body, there is a special region referred to as the axon hillock.

    Glial Cells

    image

    Glial cells, or neuroglia or simply glia, are the other type of cell found in nervous tissue. They are considered to be supporting cells, and many functions are directed at helping neurons complete their function for communication. The name glia comes from the Greek word that means “glue,” and was coined by the German pathologist Rudolph Virchow, who wrote in 1856: “This connective substance, which is in the brain, the spinal cord, and the special sense nerves, is a kind of glue (neuroglia) in which the nervous elements are planted.” Today, research into nervous tissue has shown that there are many deeper roles that these cells play. And research may find much more about them in the future.

    Figure 10.2 Glial Cells

    image

    image

    A

    LAB 10 EXERCISE 10-1

    image

    B

    Identify the parts of a neuron: Label the following: Axon, Synaptic cleft, Receptor, Neurotransmitter, Synaptic terminal, Vesicles, Voltage-gated ion channels.

    1

    2

    4

    2

    1

    5

    4

    6

    3

    5

    3

    7

    image

    LAB 10 EXERCISE 10-2

    Match these items or actions to their locations on a neuron: graded potentials, action potentials, neurotransmitter-filled vesicles, neurotransmitter receptors, voltage-gated sodium channels, ligand-gated ion channels, EPSPs, IPSPs, pre-synaptic membrane, post-synaptic membrane, Genes (that encode receptor proteins).

    Dendrites:

    Axon:

    Nucleus:

    Axon terminal

    LAB 10 EXERCISE 10-3

    image

    6

    Label the following glia & related items: Astrocyte, Perivascular feet, Oligodendrocyte, Microglia, Ependymal cell, Cerebrospinal fluid (CSF), Extracellular fluid (ECF), Neuron, Capillary.

    1

    4

    2

    7

    8

    9

    10

    3

    5

    Name 2 types of glia not represented in this picture. Why aren’t

    they in this picture?

    LAB 10 EXERCISE 10-4

    image

    LABEL THE HISTOLOGICAL SECTIONS:

    1

    2

    3

    4

    5

    6

    8

    Name the organ this sample was taken from:

    Name the organ this sample was taken from:

    7

    Obtain slides of each of the following tissues, observe them, draw and label the significant features. SLIDES: Spinal cord, cerebral cortex, cerebellum, dorsal root ganglion, peripheral nerve, neuromuscular junction:

      1. Obtain a slide of nervous tissue from the slide box. Use any nervous tissue except peripheral nerve, there are no nerve cell bodies in a peripheral nerve section.

      2. View the slide on the second-highest objective. Search carefully until you find a clear, representative neuron in your field of view.

      3. In the circles below, draw the neuron you found. Only draw the single neuron. Do not draw any of the other material. Draw your structures proportionately to their size in your microscope’s field of view.

      4. Label any neural parts you can clearly recognize.

        image

        Type of nerve tissue:

        Type of nerve tissue:

        image

        .

        Type of nerve tissue:

        image

        Type of nerve tissue:

        Type of nerve tissue:

        Type of nerve tissue:

         Anatomical divisions:

        • Central nervous system

           Brain

           Spine

        • Peripheral nervous system

           Nerves

           Functional divisions:

        • Somatic nervous system

        • Autonomic nervous system

           Sympathetic nervous system

           Parasympathetic nervous

          system

          Histology:

           Neurons

        • Cell body

        • Nuclei

        • Axon

        • Axon hillock

        • Myelin sheath

        • Nodes of Ranvier

        • Telodendria

        • Axon terminal

        • Dendrite

        • Synaptic cleft

           Neuroglia

        • Schwann cells

        • Oligodendrocytes

        • Satellite cells

        • Astrocytes

        • Microglial cells

        • Ependymal cells