EX: 15, Quiz 4

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EX: 15, Quiz 4
2014-04-21 03:01:13
StudyGuide Quiz LabPractical

Biology 103A
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  1. 4 Types of Central Neuroglia
    • 1. Astrocytes
    • 2. Microglia
    • 3. Oligiodendrocytes
    • 4. Ependymal cells
  2. Astrocytes
    • Structural: anchors neurons in place
    • Maintenance: acts as an intermediary between capillary and neuron; secrete growth factors; provide cholesterol
    • Signaling: gap junctions link neighboring astrocytes and act to spread excitation by calcium waves and the release of chemical messengers
    • Clean up: mops up ions, neurotransmitters, and K ions
    • Most numerous and versitile type of CNS glial cell
  3. Microglia
    • fulfill immune functions including transforming into phagocytes to eliminate of unhealthy neurons
    • Defensive cells in the CNS
  4. Oligiodendrocytes
    • form the myelin sheaths of white matter. Myelin speeds up AP speed 100x and electrically insulates axons from each other
    • Have process that form myelin sheaths around CNS nerve fibers
  5. Ependymal cells
    • ciliated cells that line CNS ventricular cavities and form CSF (cerebral spinal fluid) that bathes and circulates inside and outside CNS
    • Line CSF cavities
  6. 2 Types of Peripheral Neuroglia
    • 1. Schwann cells
    • 2. Satellite cells
  7. Schwann cells
    surround all nerve fibers in the PNS and form myelin sheaths around the thicker nerve fibers, functionally similar to oligodendrocytes, and vital to regeneration of damaged peripheral nerve fibers
  8. Satellite cells
    encapsulate and provide protection and support for the cell bodies of peripheral neurons in the many peripheral ganglia
  9. neuroglia or glial cells
    • - serve the needs of the delicate neurons by bracing and protecting them
    • - act as phagocytes (microglial cells)
    • - myelinate the cytoplasmic extensions of the neurons (oligodendrocytes and Schwann cells)
    • - play a role in capillary-neuron exchanges, and control the chemical environment around neurons (astrocytes)
  10. neurons
    the basic functional units of nervous tissue, transmit messages from one part of the body to another in the form of nerve impulses
  11. cell body
    • - slender processes extend
    • - is both the biosynthetic center of the neuron and part of its receptive region
  12. nuclei
    clusters of nerve cell bodies in the CNS
  13. ganglia
    clusters of neuron cell bodies in the PNS
  14. neurofibril
    the cytoskeletal elements of the neuron that have a support and intracellular transport function
  15. Nissl (chromatophilic) bodies
    an elaborate type of rough endoplasmic reticulum involved in the metabolic activities of the cell
  16. dendrite
    • branching neuron process that serves as a receptive or input region
    • transmits an electrical signal toward the cell body
  17. axons
    nerve fibers, generate and conduct nerve impulse
  18. tracts
    bundles of axons in the CNS
  19. nerves
    bundles of axons in the PNS
  20. axon collaterals
    one or more process formed branching by the axon
  21. axon hillock
    the initial region of the axon arises from a cone shaped area of the cell body
  22. axon terminals
    the knoblike distal endings of the terminal branches
  23. synapses
    junctions with neurons or effectors
  24. synaptic cleft
    fluid-filled space at a synapse
  25. myelinated fibers
    long nerve fibers which are covered with a fatty material
  26. myelin sheath
    fatty insulating sheath that surrounds all but the smallest nerve fibers, increases the speed of action potential conduction from the initial segment to the axon terminals
  27. outer collar of perinuclear cytoplasm
    refers to the peripheral part of the Schwann cell and its exposed plasma membrane
  28. myelin sheath gaps or nodes of Ranvier
    the gaps or indentations in the sheath, to allow the nerve impulses to move along the neuron by depolarization and repolarization of the nerve membrane, found voltage gated Na+ and K+ channels
  29. unipolar neurons
    • one very short process, which divides into peripheral and central process, extends from the cell body
    • Function: only the most distal parts of the peripheral process act as receptive endings; the rest acts as an axon along with the central process
    • found in dorsal root ganglion cell
  30. pseudounipolar neurons
    more accurately called unipolar neurons because they are derived from bipolar neurons
  31. bipolar neurons
    • two processes attached to the cell body, one dendrite and one axon, quite rare
    • Function: dendrite is specialized to receive a specific stimulus and axon conducts action potentials to the CNS
    • typically found only as part of the receptor apparatus of the eye, ear, and olfactory mucosa
  32. multipolar neurons
    • have many processes issue from the cell body - all classified as dendrites except for a single axon
    • found in the brain and spinal cord
    • Function: act as motor neuron which carry impulses from the CNS to the viscera and/or body muscles and glands
  33. sensory (afferent) neruons
    • neruons carry impulses from sensory receptors in the internal organs (viscera), the skin, skeletal muscles, or joints, or special sensory organs
    • the cell bodies of sensory neurons are always found in a ganglion outside the CNS
    • these neurons are typically unipolar
  34. motor (efferent) neurons
    • neurons that carry impulses from the CNS to the viscera and/or body muscles and glands
    • their cell bodies are almost always located in the CNS
    • these neurons are multipolar
  35. interneurons
    • association neurons, are situated between and contribute to pathways that connect sensory and motor neurons
    • their cell bodies are always located within the CNS
    • these neurons are multipolar
  36. sensory (afferent) nerves
    conduct impulses only toward the CNS, ex: cranial nerves
  37. motor (efferent) nerves
    carry impulses only away from the CNS, ex: ventral roots of spinal cord
  38. mixed nerves
    nerves carry both sensory (afferent) and motor (efferent) fibers, ex: all spinal nerves
  39. endoneurium
    fine areolar connective tissue that surrounds each nerve fiber
  40. perineurium
    fibrous connective tissue that surrounds a bundle of nerve fibers
  41. fascicles
    bundles of fibers formed by perineurium
  42. epineurium
    a white, fibrous connective tissue sheath that surrounds the whole nerve
  43. function of myelin
    to protect and insulate the axons and enhance their transmission of electrical impulses
  44. Purkinje cells
    belong to motor neuron because of cerebellum's 1st output (smooth coordination' motor), and found in multipolar neuron
  45. Pyramidal cells
    belong to 1st motor cortex and found in multipolar neuron
  46. motor neurons
    belongs to motor neurons