Neurons

• What is the role of a neuron?

  To receive and send information around the brain and body.
• What are three types of neurons?

  Motor neurons, sensory neurons, interneurons.
• What is a dendrites function?

  Dendrites: receives signals/information from environment or other cells.
• What is a soma function?

  Soma/cell body: contains cell organelles. Impulses/signal travels from dendrites through here to the axon.
• What is an axon function?

  Axon: sends/transport the signal/impulse from the soma to the axon terminal.
• What is an myelin sheath function?

  Myelin sheath: fatty coating that protects the axon and increases the speed of impulses.
• What is an axon terminal function?

  Axon terminal: receives impulse, releases neurotransmitters to do a job.
• What are sensory neuron?

  Sensory neuron: transmit impulses from the body's sensory receptors to the CNS.
• What are interneurons?

  Interneurons: live within the CNS, transmit impulses between the sensory neurons and the motor neurons, and is the most abundant type.
• What are motor neurons?

  Motor neurons: transmit impulses from the CNS to the body's muscles and glands that can respond to the stimulus.
• What are oligodendrocytes?

  Oligodendrocytes: wrap around the CNS Neurons, form a myelin sheath that speeds up neuron transmission.
• What are astrocytes?

  Astrocytes: star shaped cells; anchor neurons to blood vessels, help the exchange of material's between neurons and blood.
• What are microglial cells?

  Microglial cells: small and thorny, act as the main source of immune defense against invading microbes in the CNS.
• What are schwaan cells?

  Schwaan cells: the PNS version of oligodendrocytes, wrap around the PNS Neurons, form a myelin sheath that speeds up transmission.
• What are the differences between unmyelinated neurons and myelinated neurons?

  
  

  Unmyelinated neurons

  • Do not have a myelin sheath
  • Nerve impulse moves down the entire length of the axon
  • Slower transmission speeds
  • Higher resistance

  Myelinated neurons

  • Have a myelin sheath
  • Nerve impulse jumps between nodes of Ranvier
  • Faster transmission speed
  • Lower resistance
• Fill in the blanks

  A) Dendrite

  B) SOMA

  C) Axon terminals

  D) Nucleus

  E) Axon

  F) Myelin sheath (around the axon)

  
• Fill in the blanks

  A) Sensory neuron

  B) Interneuron

  C) Motor neuron

  D) Sensory receptor

  E) CNS

  F) Muscle/Gland