Sensory, Relay and Motor neurons

• Sensory Neuron and its functions:

  • Sends info from the peripheral nervous system to the Central nervous system
  • Keeps the brain informed about internal and external info from the environment coming from the sense organs.
  • Can only transmit messages one way and cannot receive messages.
  • Have long dendrites and short axons.
  • Cell body is usually to the side of the cell
• Relay neuron and its functions:

  • Connect sensory neuron to motor neuron
  • Located in the Central nervous system
  • Carries messages across the Central nervous system
  • Messages can be both transmitted and received
  • They have short axons and long dendrites
• Motor neuron and its functions:

  • Carry signals from the central nervous system towards the organs, muscles and glands
  • Can transmit and receive messages
  • Control physical movements such as contraction and relaxation of muscles
  • Have short dendrites and long axons
• What does the cell body contain?

  Nucleus - where DNA is stored.
• What is an Axon?

  A long, slender projection of a nerve cell that conducts electrical impulses away from the cell body.
• What covers the Axon?

  Myelin Sheath
• What is a Myelin Sheath?

  Fatty and protective covering for the Axon
• What are Nodes of Ranvier?

  Gaps between Myelin Sheath which speed up the messages transmission
• What are Terminal Knobs and where are they found?

  Found at the end of thee neuron and communicate across the synaptic cleft to the next neuron.