Nervous Tissue

Nervous tissue is responsible for sensing stimuli and transmitting signals to and from different parts of an animal.

Nervous Tissue: Neurons

Neurons are the basic unit of nervous tissue.

As we have previously discussed, structure and function are very much intertwined within biology and the structure of a neuron is uniquely suited to its function within nervous tissue.

A neuron consists of two major parts:

• Cell Body
  
  The central cell body contains the neuron's nucleus, associated cytoplasm, and other organelles.
  
  
• Nerve Processes
  
  Nerve processes are "finger-like" projections from the cell body that are able to conduct and transmit signals. There are two types:
  
  Axons - typically carry signals away from the cell body.
  
  Dendrites - typically carry signals toward the cell body.
  
  

Neurons usually have one axon (can be branched however). Axons usually terminate at a synapse through which the signal is sent to the next cell, most often through a dendrite.

Unlike axons, dendrites are usually more numerous, shorter and more branched. As with other structures in organisms, there are exceptions.

Bundles of axons and dendrites are called nerves. They are sensory if they consist of dendrites only, motor if they consist of axons only and mixed if they consist of both.

Animal Tissue Types

To learn more about animal tissues, visit:

• Nervous Tissue - Glia
  
• Epithelial Tissue
  
• Connective Tissue
  
• Muscle Tissue