201 unit 9

  1. what are the 3 overlapping functions of the nervous system?
    • sensory
    • integration
    • motor output
  2. what is the sensory funtion of the nervous system?
    senory receptors monitor and changes inside and outside of the body
  3. what is integration?
    processes and interprets sensory input;makes the decisions
  4. what is motor output?
    it dictates a response by activating effector organs
  5. what is the CNS and what does it contain?
    • it is the integrating and command center
    • consists of the brain and spinal cord
  6. what does the PNS consist of?
    it consists of the nerves and Ganglia
  7. what happens in the sensory (affrent) division?
    signals get picked up by sensory receptors are carried by nerve fibers from the PNS to the CNS
  8. what is somatic sensory?
    • sense of structures external to the ventral bodyor of the outer tube.
    • eg: skin, skeletal musculature, bones
  9. what are general somatic senses?
    • widely spread receptors
    • eg: touch,pain,pressure,temp.
  10. what are proprioceptive senses?
    • they detect stretch in tendons and muscles
    • body sense= position and movement of body in space
  11. what are special somatic senses?
    • hearing
    • balance
    • vision
    • smell
  12. what are visceral sensory?
    • sense of the viscer within the ventral body cavity or structures of the inner tube
    • eg: digestive tube,lungs, heart, bladder
  13. what are the general visceral senses?
    • stretch
    • pain
    • temp
    • nausea
    • hunger
    • felt in the gi tract and urinary tract and reproductive organs
  14. what is the special visceral sense?
  15. what happens in the motor (efferent) division?
    signals are carried away from the CNS to the PNS; innervate muscles and glands
  16. what does somatic motor do?
    • signals the contraction of skeletal muscles
    • it is under voluntary control
    • it is called the voluntary nervous system
  17. what does visceral motor do?
    • regulates the contraction of smooth muscle ,cardiac muscle,and glands
    • controls the function of visceral organs
  18. what are 2 other names for the visceral motor?
    • the autonomic nervous system
    • or the involuntary nevous system
  19. what are the 2 major cell types?
    • neuroglial
    • neuron
  20. what are neuroglial cells?
    • they are suppport cells
    • connective cells not nervous
    • non excitable
    • surround and wrap neurons
  21. what are neurons?
    • nervous cell
    • transmits electrical impulses
  22. what are the 6 types of neuroglial cells?
    • astrocytes
    • microglial cells
    • ependymal cells
    • oligodendrocytes
    • satellite cells
    • schwann cells
  23. what are astrocytes?
    • most abundant cell in CNS
    • take up and release ions to control the environment around neurons
    • recapture and recycle neurotransmitters
    • invovled with synapse formation in developing neural tissue
    • produce molecules necessary for neural growth
    • form the blood brain barrier
  24. what are microglial cells?
    • smallest and least abundant in CNS
    • act as phagocytes;the macrophages of the CNS
    • engulf invading microorganisms and dead neurons
    • derived from blood cells called monocytes
  25. what are ependymal cells?
    • found in the CNS
    • line the central cavity of the spinal cord and brain
    • bear cilia which circulate spinal fluid
  26. what are oligodendrocytes?
    • wrap their cell processes around axons in CNS
    • which produces myelin sheaths for the CNS
  27. what are satellite cells?
    they surround neuron cell bodies within ganglia in the PNS
  28. what are schwaan cells?
    • they surround axons in the PNS
    • they preform an insulating layer
    • prevent a leakage of currant
    • increase the speed of impulse conduction(actionpotential)
  29. what are mylein sheaths?
    segmented structures composed of the lipoprotein myelin
  30. what is the neurilemma?
    thin layer of material external to myelin layers
  31. what are the nodes of ranvier?
    gaps along the axon where there are no myelin
  32. overview of neurons?
    • basic structure of the nervous system
    • they conduct electrical impulses called action potential along the plasma membrane
    • they live for a lifetime
    • they do not divide
    • they have a high metabolic rate
  33. what are nissl bodies?
    clusters of rough ER
  34. what are nuclei?
    clusters of neuron cell bodies located in the CNS
  35. what are ganglia?
    clusters of neuron cell bodies located in the PNS
  36. what are dendrites?
    short neuron processes (fibers) that transmit electrical singals toward the nerve cell body
  37. what is the axon?
    • the long neuron process (fiber)
    • impulse generator and conductor
    • each neuron has only one
    • transmits impluses away from the cell body
  38. where does action potential begin?
    at the axon hillcock
  39. where do axons end?
    at knobs called axon terminals or synaptic knobs
  40. what are tracts?
    bundles of axons located in the CNS
  41. what are nerves?
    bundles of axons located in the PNS
  42. what are multipolar neurons?
    • more than 2 processes attatched to the cell body (usually many dendrites and one axon)
    • the most common type
  43. what are bipolar neurons?
    • two processes attached to the cell body
    • they are rare only found in some special sense organs like retina of the eye
  44. what are unipolar neurons?
    only a single process axon attatched to the cell body
  45. how are the structures of neurons classified?
    based on the numer of processes attatched to the cell body
  46. how are the funtions of neurons classified?
    based on the direction the nerve impulse travels
  47. what are sensory (afferent) neurons?
    • transmit impulses from the PNS to CNS
    • all are unipolar
    • neuron cell bodies found in ganglia within in PNS
  48. what are motor (efferent) neurons?
    • trnsmits from the CNS to PNS
    • most are multipolar
    • neuron cell bidies found in CNS
  49. what are interneurons (association neuron)?
    • confined to the CNS
    • most are multipolar
    • found between motor and sensory neurons
    • neuron cell bodies located in CNS
  50. where are mechanically gated ion channels found?
    what do they open in response to?
    • found in sensory neurons
    • open in reponse to physical force like stretch pressure
  51. what do chemically gated ion channels respond to?
    respond to a variety of chemicals like neurotranmitters or intralcellular signal molecules
  52. why are voltage gated ion channels important?
    important in the initiation and conduction of electrical signals action potential
  53. ions move ____ their concentration gradients, from _____solute concentration to _____ solute concentration.
    • down
    • high
    • low
  54. in the Na+ K+ pump how many NA+ and K+ are pumped in or out/
    3 Na+ are pumped out for every 2 K+ brought in the cell
  55. electrical disequillibrium in the boddy is known as?
    membrane potential or resting membrane potential
  56. what is the equilibrium potential for K+?
    -90 mV
  57. what is the equilibrium potential for Na+?
  58. what is the average resting potential for the cell?
  59. what does the sodium potassium pump do?
    it maintains the resting membrane potential.
  60. what is the absolute refractory period?
    the period of time where a second action potential can not be triggered no matter how large the stimulus
  61. what is the relative refractory period?
    • it follows the absolute refractory period
    • the time when the depolarization potential is higher than normal it can iniate another action potential.
  62. what 2 things increase conduction velocity?
    • the diameter the thicker the axon the faster the action potential
    • how well the axon is insulated with mylein, the more mylein the faster the action potential
  63. what is saltatory conduction?
    conduction along a myleinated axon
  64. what is multiple sclerosis?
    • symptoms include vision loss increased muscle weakness
    • destroys mylein sheath of the CNS axons
    • it stops action potential because there is to much distance between the nodes of ranvier
Card Set
201 unit 9
unit 9 201