Development of Nervous Tissue S1M1

  1. CNS appears at the beginning of the 3rd week as the
    neural plate
  2. The neural plates lateral edges soon elevate to form the
    neural foldsImage Upload 1
  3. The wall of neural groove is lined with a thick
    Pseudostratified epithelium
  4. Once the neural tube closes, neuroepithelial (inner wall of the neural groove) cells begin to give rise to the
    Primitive nerve cells, or neuroblasts
  5. The wall of neural groove is lined with a thick pseudostratified epithelium called
    neuroepithelial cells, or neuroepithelium
  6. Nerve cells in the spinal cords are derived from
    neuroblasts (primitive nerve cells)
  7. Once neuroblasts form, they lose their ability to
  8. Axons of neurons in the basal plate break through the marginal layer and become the
    Ventral root of the spinal nerveImage Upload 2
  9. Schwann cells do what
    Myelinate the peripheral nerve, beginning at month 4 of fetal life
  10. Nerve fibers in CNS do not become myelinated until the
    First year of postnatal life.
  11. Glial cells in CNS (except microglia) are derived from
  12. Microgila are derived from the
    Bone marrow (mesenchyme)
  13. Glial cells in PNS such as Schwann cells, sensory ganglia, and sensory fibers are derived from
    The neural crest cells
  14. The cephalic end of the neural tube
    shows three dilations called
    Primary brain vesicles
  15. The lumen of the spinal cord is continuous with that of the
    Brain vesicles
  16. Rhombencephalon/Hindbrain consists of
  17. The myelencephalon is,
    the most caudal of the brain vesicles
  18. Myelencephalon gives rise to the
  19. Metencephalon form the
    cerebellum and the pons
  20. Mesencephalon gives rise to the
  21. The Superior colliculus receive direct input from the
  22. Inferior colliculus receives information from the
  23. Inferior colliculus functions as a relay station en route to the
  24. The Prosencephalon is more commonly known in a developed brain as the
  25. Telencephalon gives rise to the
    Cerebral hemispheres
  26. Diencephalon gives rise to what structures
    • Optic cup and stalk, part of pituitary gland, Thalamus, hypothalamus, and pineal
    • gland
  27. The most caudal part of the roof
    plate develops into the
    pineal gland
  28. Pituitary gland has what two origins
    • 1. ectodermal outpocketing of the stomadeum known as Rathke’s pouch
    • 2. A downward extension of the diencephalon, the infundibulum
  29. Pharyngeal hypophysis
    is a small portion of Rathke’s pouch persists in the roof of the pharynx (defect)
  30. Craniopharyngiomas may cause
    hydrocephalus and pituitary disfunction
  31. Spina bifida is a
    general term for a Neural Tube Defect affecting the spinal region. It consists of a splitting of the vertebral arches.
  32. Most defects of the spinal cord result from
    abnormal closure of the neural folds in weeks 3 and 4 of development.
  33. Anencephaly
    • failure of the cephalic part of the neural tube to
    • close. As a result, the vault of the skull does not form, and the malformed brain tissue degenerates.
  34. Many defects of the CNS may occur without
    much external manifestation
  35. The leading cause of mental
    retardation is
    maternal alcohol abuse
  36. I (Olfactory) and II (Optic) nerves arise from the
  37. III (Oculomotor) arises
    outside the hindbrain
  38. Development from IV to XII nerves,
    arises from in the hindbrain.
  39. Segmentation patterns in the brain and mesoderm appear by
    the 25th day of development
  40. The hindbrain is divided into eight rhobomeres
    (r1-r8), and these structures give rise to
    The cranial motor nerves.
  41. In the hindbrain, proliferation centers in the neuroepithelium establish eight distinct regions called
  42. Cranial nerve sensory ganglia are outside of the brain and they originate from
    • ectodermal placodes (ectodermal thinkenings) and
    • neural crest cells
  43. Epibranchial placodes contribute to ganglia for nerves of the
    pharyngeal arches (V, VII, IX, and X)
  44. Parasympathetic ganglia are derived from
    neural crest cells
  45. Parasympathetic ganglia and their fibers are carried by
    Cranial Nerves III, VII, IX, and X.
  46. Sympathetic nervous system originate from the
    neural crest of the thoracic region
  47. Adrenal gland arises from
    • Cortex is derived from mesoderm
    • Medulla is derived from neural crest
  48. Postganglionic fibers for the parasympathetic nervous system arise from
    ganglia derived from neural crest cells
  49. Congenital megacolon (Hirschsprung Disease) Results from a failure of
    • parasympathetic ganglia to form in the wall
    • of part or all of the colon and rectum because the neural crest cells fail to migrate.
  50. Where do the nueral crest cells originate from
    As the neural folds elevate and fuse, cells along the lateral border dissociate from neighboring cells.Image Upload 3
  51. Neural Crest cells undergo what unique transition
    Epithelial to Mesenchymal transformation
  52. Migration of the neural cells is determined by what two properties
    Intrinsic and extrinsic
  53. How is migration of the neural cells regulated
    High levels of chrondroitin sulfate
  54. When do the neural cells begin to migrate
    Around the third week of development
  55. What are the two hypothesis's of how the cells are differentiated
    Determined by the environment, and they are already programmed. Both have been shown to effect the development
  56. What are some of the structures that are derived from the neural crest cells
    • Connective tissue
    • Bones of the face and skull
    • Cranial nerve ganglia
    • Dermis on face
    • Dorsal root ganglia
    • Adrenal medulla
    • Glial cells
    • Forebrain
    • Melanocytes
    • Smooth muscle cells
  57. Neural Cranial cells are the only cells that will develop into
  58. Neural crest cells are not irreversibly fixed to
    differentiate to a specific path
  59. NC cells to from the trunk region will become
    Sympathetic Neurons and will produce norepinephrine (Dorsal root ganglia)
  60. NC cells to from the cranial region will become
    Parasympathetic neurons and will produce acetocholine
  61. The factors that the neural crest cells are exposed to determines
    Their fate
  62. What are the three regions of neural crest cells
    • Cranial
    • Circumpharyngeal
    • Trunk
  63. What are the two sub portions of the circumpharyngeal area
    Vagal and sacral cardiac
  64. The trunk area of the neural crest cells are located
    From the 6th somite to the most caudal somites
  65. Trunk cells that travel ventrally will differentiate into
    Adrenal medulla and sympathetic nervous system
  66. What portion of the neural creat do the melanocytes derive from
    The cells that migrate dorsalaterally from the trunk
  67. The neural cells that form the parasympathetic innervation to the gut come from
    Circumpharyngeal vagal area (somite 1-7) and sacral area (Past somite 28)
  68. Cardiac Neural Crest cells arise from where
    Somite 5
  69. DiGeorge Syndrome is the reduced function of the thymus, thyroid, and parathroid, as well as heart abnormalities. Defects in what crest site would cause this
    Disturbance in the cardiac crest of the circumpharyngeal area
  70. The cranial neural crest cells do not express
    HOX genes
  71. Some of the cells in the R3 and R5 region do what under the presence of BMP4Image Upload 4
    Undergo Apoptosis
  72. What regions of the cranial portion of the neural crest will make up cranial sensory ganglia 5,7,9,10
    Image Upload 5
  73. What bones of the skull arise from neural crest cells
    • Image Upload 6
    • The blue ones
  74. Cleft palets and lips are from a defect in what developing cells
    Neural crest cells
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Development of Nervous Tissue S1M1