Chapter 10 Notecards

  1. What is the central nervous system (CNS)?
    brain and spinal cord
  2. What is the peripheral nervous system (PNS)?
    all the nerves; a division of the PNS is the autonomic nervous system (ANS)
  3. What are the two principal divisions of the nervous system?
    the central nervous system and the peripheral nervous system
  4. What are the two types of cells found in the nervous system?
    neurons, or nerve cells, and glia, specialized connective tissue cells
  5. What is the direction of neural transmission from sensory neurons and motor neurons?
    Sensory neurons transmit impulses TO the spinal cord and brain; motor neurons transmit impulses AWAY from the brain and spinal cord.
  6. What are the three parts of a neuron?
    • Cell body of neuron—main part
    • Dendrites—branching projections that conduct impulses to cell body of neuron
    • Axon—elongated projection that conducts impulses away fromcell body of neuron
  7. What is the function of sensory neurons?
    conduct impulses to the spinal cord and brain; also called afferent neurons
  8. What is the function of motor neurons?
    conduct impulses away from brain and spinal cord to muscles and glands; also called efferent neurons; only conduct impulses to muscle and glandular epithelial
  9. What is the function of interneurons?
    conduct impulses from sensory neurons to motor neurons; also called centralor connecting neurons
  10. What is the function of glia cells?
    Glia cells hold the functioning neurons together, protect them, and regulate neuron function.
  11. How are the three types of glia different?
    1] Astrocytes are relatively large, star-shaped cells that attach to neurons and small blood vessels to hold these structures close to each other. [2] Microglia usually remain stationary but in inflammation or degeneration of the brain, they enlarge, move about, and act as microbe-eating scavengers. [3] Oligodendrocytes help hold nerve fibers together and also produce the fatty myelin sheath
  12. What is myelin?
    Myelin is a white, fatty substance.
  13. What is multiple sclerosis?
    ˜characterized by myelin loss in central nerve fibers and resulting conduction impairments
  14. What are tumors?
    • General name for nervous system tumors is neuroma
    • Most neuromas are gliomas, glial tumors
    • Multiple neurofibromatosis—characterized by numerous benign tumors
  15. Where is myelin produced in the central nervous system?
    in oligodendrocytes
  16. Where is myelin produced in the peripheral nervous system?
    in Schwann cells
  17. How might symptoms differ according to where myelin production is being impaired?
    Symptoms will depend on the nerve affected as well as the area of the nerve affected.
  18. What is white matter composed of?
    Nerve fibers usually have a myelin sheath, and myelin is white.
  19. What is gray matter composed of?
    Tissue composed of cell bodies and unmyelinatedaxons and dendrites is called gray matter because of its characteristic gray appearance.
  20. What is a nerve?
    A bundle of peripheral axons
  21. What is a tract?
    A bundle of central axons
  22. What are nerve coverings?
    fibrous connective tissue
  23. How would you describe the coverings that surround an axon?
    Each axon is surrounded by a thin wrapping of fibrous connective tissue called the endoneurium. They are then bundled together, called fascicles, and wrapped in an outer layer of perineurium. The whole nerve is then surrounded by the tough sheath, epineurium.
  24. What is the difference between a neuron pathway and a reflex arc?
    A reflex arc is the simplest type of neuron pathway
  25. What is a two-neuron arc?
    • The simplest type of reflex arc consisting of only two types of neurons: sensory neurons and motor neurons.
    • knee-jerk reflex
  26. What is a three-neuron arc?
    It consists of three different types of neurons: sensory neurons, motor neurons, and interneurons
  27. What are action potentials?
    Action potentials are conducted from receptors to effectors over reflex arcs;˜conduction by a reflex arc results in a reflex (that is, contraction by a muscle or secretion by a gland)
Card Set
Chapter 10 Notecards
Chapter 10 Nervous System notes for Dr. B's class