Book: chapter 12

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Book: chapter 12
2014-11-12 01:16:00
chapter 12 bio120
Exam 3
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  1. The whole nerve is covered by a tough fibrous sheath called ______.
    • epineurium
  2. Groups of axons are bound into bundles called ___a___ and wrapped by a CT called the ___b___.
    • a) nerve fascicles
    • b) perineurium
  3. within a nerve, each axon is surrounded by schwann cells, and covering those schwann cells is a layer of loose CT called this ____.
    • endoneurium
  4. This is a cablelike organ in the PNS
  5. In two regions of the brain, there is an additional layer of gray matter located superficially
  6. within the white matter, axons traveling to similiar destinations form axon bundles called this.
  7. This color matter contains no neuron cell bodies but millions of axons and neuroglia
    white matter
  8. What is the site where neuron cell bodies are clustered and where synapses occur?
    gray matter
  9. This zone in the CNS surrounds the hallow central cavity. In the spinal cord it is butter-fly shaped
    gray matter
  10. this type of myeline sheath wraps has processes that wrap several different axons, and are widely spaced throughout the axon. Is it found in the PNS or CNS?
  11. Axons that lack a myelin sheathe are called this. They can wrap 15 or more of these type of axons.
    Nonmyelinated axons.
  12. these gaps increase seed impulse conduction along the axon
    myelin sheath gaps
  13. what are the 3 functions of the myelin sheath?
    • 1. prevent leakage from axons
    • 2. increase speed of impulse conduction
    • 3. makes impulse proagation more energy-efficient
  14. myelin sheaths are produced from ___a___ in the CNS and from ___b___ in the PNS.
    • a) oligodendrocytes
    • b) schwann cells
  15. This type of neuroglia in the PNS surround all axons in the  PNS and form myelin sheaths
    schwann cells
  16. This tye of neuroglia in the PNS surround neuron cell bodies within ganglia
    satellite cells
  17. What are the 2 types of neuroglia in the PNS?
    • 1. satellite cells
    • 2. schwann cells
  18. This glial cell, ___a___, line up groupps and wrap their cell processes around the thicker axons in the CNS, producing insulating coverings called ___b___
    • a) oligodendrocytes
    • b) myelin sheaths
  19. This cell functions to pprovide a permeable layer between the cerebrospinal fluid that fills up the cavity and tissue fluid that bathes the cells of the CNS
    ependymal cells
  20. Like other macrohages of the body, microglial cells are derived from blood cells called this.
  21. this neuroglia are the phagocytes and macrophages of the CNS, engulfing injured or dead neurons
    microglial cells
  22. This type of glial cell is the smallest and least abundant of the CNS
    • microglial cells
  23. this type of glial cell helps synapses form by develoing neural tissue, produces molecules for neural growth, and propagate calcium signals for memory
  24. What are the 3 functions of astrocytes?
    • 1. regulates neurotransmitter levels
    • 2. signals increased blood flow in active regions of the brain.
    • 3. controlling he ionic environment around neurons
  25. This type of glial cell is the most abundant. Its radiating processes cling to either neurons or capillaries.
    • astrocytes
  26. T or F: glial cells cannot divide
  27. This cell type outnumber neurons in the CNS 10 to 1 and make up half the mass of the brain
  28. this non-nervous suoprting cell covers parts of the neurons, insulating them to help eletrical activities interfering with adjacent neurons (2 names)
    neuroglia or glial cells
  29. This class makes up 99.98% of neurons in the body. They are all in the CNS and lie between the other 2 classes of neurons
  30. this tye of neurons are multipolar, and their cell body are located in the CNS. they form junctions with effector cells that stimulate muscle contraction
    motor neuron
  31. the efferent neurons make up the _____ division of the PNS.
    motor division
  32. Most of these types of neurons are pseudounipolar and their cell bodies are in ganglia outside the CNS
    sensory neuron
  33. afferent neurons make up the ____ division of the PNS
  34. what are the 3 functional classifications of neurons
    • 1. sensory
    • 2. motor
    • 3. interneurons
  35. T or F: unipolar neurons do not contain dendrites
    • true: both peripheral and central processes are considered axons
  36. T or F: the peripheral process of the unipolar neuron is considered the axon
    • False: the central process is an axon because it carries a nerve impulse AWAY from the cell body
  37. In unipolar neurons, the process that runs into the CNS is the (a) and the other that extends to the receptors is called the (b)
    • a) central process
    • b) peripheral process
  38. this class of neuron can be found in the sensory ganglia in the PNS, where they function as sensory neurons
    unipolar neurons
  39. This neuroon starts out as a bipolar neuron whose 2 processes fuse together (2 names)
    unipolar neuron or pseudounipolar neuron
  40. this class of neuron is very rare; occuring in some special sensory organs (inner ear, retina of eye) where they mostly serve as sensory neurons. They have 2 processes
    • bipolar neurons
  41. which class of neuron contain 99% of neurons in the body
    multipolar class
  42. This class of neuron has numerous dendrites, a single axon (sometimes none), and have more than 2 processes
    • multipolar neuron
  43. what are the 3 structural classifications of neurons?
    • 1. multipolar 
    • 2. bipolar
    • 3. unipolar
  44. At the synapse, the plasma membranes of the two neurons are seperated by this.
    • synaptic cleft
  45. T or F: mitochondria are not abundant in terminal boutons
  46. These are membrane-bound sacs filled with neurotransmitters contained in the terminal bouton.
    • synaptic vesicles
  47. This synapse occurs between axons and neuron cell bodies
    • axosomatic synapse
  48. This is where most synapses occur: between the terminal boutons of one neuron and the denrites of another neuron
    • axodendritic synapse
  49. this neuron transmits signals AWAY from the synapse
    postsynaptic neuron
  50. This neuuron conducts signals TOWARDS the synapse
    presynaptic neuron
  51. some CNS transmit signals electrically through this
    gap junctions
  52. What is the site at which neurons communicate
    • Synapse
  53. the ends of the terminal arborization branches are called
    terminal boutons
  54. This is at the end of an axon where it starts to branch profusely
    • terminal arborization
  55. Branches of axons are called this
    axon collaterals
  56. T or F: the bigger diameter of an axon, the slower the impulses are
    F: the faster the impulses are
  57. A long axon is called
    a nerve fiber
  58. The movement of substances along axons is through this
    axonal transport
  59. by definition, these are impulse generators and conductors that transmit nerve impulses away from their cell body
  60. This is where the axon attaches to the cone-shaped region of the cell body
    • axon hillock
  61. what are the two types of processes in the neuron?
    dendrites and axons
  62. Where do the clusters of ganglia lie along
    the nerves in the PNS
  63. These are bundles of intermediate filaments that keep the cell from being pulled apart from tensile forces
  64. these organelles continuilly renew the membranes of the neural cell and protein components of the cytosol
    chromatophilic substance
  65. this is a large cluster of rER and free ribosomes in the cell body
    chromatophilic substance
  66. in all cell bodies, what do they all have in common?
    all consist of a single nucleus surrounded by cytoplast
  67. these have a high metabolic rate and cannot survive for more than a few mins without oxygen
  68. T or F: neurons have an extreme longevity and can live for over 100 years
  69. Neurons conduct 2 electrical signals called these:
    nerve impulses and action potentials
  70. these are highly specialized cells that conduct electrical signals from one part of the body to another
  71. neurons and nerogliaboth develo from these two embryonic tissue
    neural tube and neural crest
  72. What are the 2 main types of cells in a nervous tissue?
    • 1) neurons: the excitable nerve cell
    • 2) neuroglia: the nonexcitable supporting cell that wraps around the neurons
  73. what is another name for the ANS
    involuntary nervous system
  74. the visceral motor makes up this and ontrols the function of the visceral organs
    autonomic nervous system (ANS)
  75. This part of the PNS regulates the contraction of smooth and cardia muscle and secretion by the body's many glands
    visceral motor
  76. this is often called the voluntary nervous system. this part of the PNS stimulate scontraction of skeletal muscles
    somatic motor
  77. This sense, forms taste and smell
    special visceral senses
  78. These series are felt widelyin the digestive and urinary tracts, reproductive organs, etc. sensations such as hunger and nausea are also felt here.
    general visceral senses
  79. these senses are confined to relatively small areas, which are mostly confined in the head for hearing, balance, or equilibium and vision
    special somatic senses
  80. this sense informs you of the position and movement of ur body and space, giving u a "body sense"
  81. These are the senses whose receptors are sppread widely throughout the outer tube of the body. primarily the senses on the skin for touch, painj, pressure, vibration, and temperature
    general somatic senses
  82. what is another name for the visceral motor?
    autonomic nervous system (ANS)
  83. What are the 4 subdivisions of the PNS
    • 1. somatic sensory
    • 2. somatic motor
    • 3. visceral sensory
    • 4. visceral motor
  84. this body region consists of structures external to the ventral body cavity, or structures of the outer tube (skin, bones)
    somatic body  region
  85. this has 2 names and they are signals picked up by a sensory receptors and are carried by nerve fibers of the PNS -> CNS
    sensory or afferent signals
  86. this is included in the PNS, which are areas where the cell bodies of neurons are clustered
  87. this consists mainly of the nerves that extend from the brain and spinal cord and is part of the nervous syste outside the CNS
    peripheral nervous syste (PNS)
  88. this consists of the brain and spinal cord. it receives incoming sensory signals, interprets it, and dictates motor responses based on past experiences, reflexes and current condition
  89. The nervous system dictates a response by activating our muscle or glands, which are called (a), through a process called (b)
    • a) effector organs
    • b) motor output
  90. the nervous system processes and interprets the sensory input and makes decisions about what should be done at each moment, in this process
  91. the gathered information of a stimulus is called this
    sensory unit
  92. sensory recetrs monitors changes in and outside the body. these changes are called this ____.