Ch. 12 Nervous System b

Card Set Information

Ch. 12 Nervous System b
2014-04-03 18:51:34
cgcc boerboom

Neuron structure
Show Answers:

  1. What is the plasma membrane of an axon called?
  2. What is the outermost layer of the schwann cell around an axon called?
    The neurilemma
  3. Soma (cell body). Control center of neuron. Contains nucleus, nucleolus, mitochondria, rough ER is called Nisll Bodies
  4. Dendrites: Input for the cell. receives signals from here.
  5. Axon hillock: enlarged portion of the cell body where the axon connects
  6. Axon: Cell output. Carries signals out to its branched end with the synaptic knobs. Changes its ion concentration to move a signal, just like muscles.
  7. Synaptic knob (bulb): The small bulge at the end of an axon, contains neurotransmitters.
  8. Myelin sheath: fatty substance around the axon, speeds up impulse transmission.
  9. Node of Ranvier: small gap between Myelin sheaths on the axon, leaves axon exposed.
  10. What is a nerve versus a neuron?
    Nerves are bundles of Axons in wrappings of fibrous connective tissue.
  11. What are interneurons?
    The decision-makers that lie only in the CNS. They receive the signals, decide what to do with them, then send out a response. They make-up 90% of all neurons!
  12. What are the three sheaths of tissue that make up nerves like unto muscles?
    • Endoneurium: Surrounds each neuron around its myelin sheaths
    • Perineurium: Surrounds each bundle of neurons (fascicle)
    • Epineurium: Surrounds the nerve as a whole