a & p chpt 9

  1. CNS
    the brain and spinal cord
  2. PNS
    made up of all the nerves outside of the CNS
  3. effector
    any tissue or organ that carries out a nervous command (muscles and glands)
  4. somatic nervous system
    nervous system that is voluntarily controlled, (by conscious will) -- its effectors are the skeletal muscles
  5. autonomic nervous sytem
    the involuntary system that controls smooth muscle, cardiac muscle, and glands
  6. myelin
    fatty material that covers some axons and insulates and protects them
  7. nodes of Ranvier
    spaces in between the schwann cells
  8. afferent nuerons
    nuerons that conduct impulses to the spinal cord and brain
  9. efferent nuerons
    carry messages away from the CNS
  10. internuerons
    relay information within the CNS
  11. nerve
    a fiber bundle in the PNS
  12. tract
    a fiber bundle in the CNS
  13. fascicles
    groupings of individual fibers
  14. endoneurium
    layer around an individual fiber
  15. perineurium
    layer around a fascicle
  16. epineurium
    layer around the whole nerve
  17. neuroglia
    • cells that support and protect the neurons
    • protect and nourish nervous tissue
    • support nervous tissue and bind it to other structures
    • aid in repair of cells
    • act as phagocytes
    • regulate the composition of fluids around and between cells
  18. synapse
    the point of junction for transmitting the nerve impulse
  19. neurotransmitters
    • chemicals used to trigger an acton potentialacross a synaptic cleft
    • slower than electrical transmission
  20. ascending tracts
    sensory impulses that enter the spinal cord and are transmitted toward the brain
  21. descending tracts
    motor impulses traveleing from the brain and to the peripheral system
  22. reflex arc
    a complete pathway thru the nervous sytem from stimulus to response
  23. simple reflex
    a rapid and uncomplicated and automatic response involving very few nuerons
  24. spinal reflex
    a simple reflex that passes thru the spinal cord alone and does not involve the brain
  25. multple sclerosis
    a disease in which the myelin sheath around axons is damaged and the nueron fibers themselves degenerate
  26. amyotrophic lateral sclerosis
    a nervous system disorder in which motor neurons are destroyed
  27. poliomyelitis
    a viral disease that multplies in the spinal cord's motor neurons, leading to paralysis
  28. dorsal root
    afferent (sensory) neurons
  29. ventral root
    efferent (motor) neurons
  30. plexus
    the larger anterior branches of spinal nerves that interlace to form networks
  31. name the three main plexuses
    • cervical plexus
    • brachial plexus
    • lumbarsacral plexus
  32. dermatomes
    allow us to map the skin of the human body using the spinal nerves
  33. functions of the Autonomic nervous system
    • increase in heart rate and force of heart contractions
    • increase in blood pressure
    • dilation of blood vessels to skeletal muscles
    • dilation of bronchial tubes
    • stimulation of the central part of the adrenal gland
    • increase in basal metabolic rate
    • dilation of pupil and decrease in focusing ability for near objects
Card Set
a & p chpt 9