Embryology Nervous System

  1. When does CNS show up in embryo development?
    Begin at week 3
  2. When does CNS sensitive period for major defects begin and how long does it last till?
    Sensitive period lasts from week 3 till 16.
  3. When does susceptibility period for minor defect for CNS development last?
    Continues through birth
  4. True/False: nervous system is sensitive to teratogens throughout almost all of gestation?
  5. Is Visceral sensory information in our conscious or not in our conscious awareness?
    Not conscious
  6. Is Somatic sensory information in our conscious or not in our conscious awareness?
  7. Autonomic nervous system is which part of the peripheral nervous system?
    Visceral motor division
  8. What are the subdivisions of autonomic nervous system?
    • Sympathetic
    • Parasympathetic
  9. What is the function of somatic motor division?
    Conscious movement of the skeletal muscle
  10. Neural tube forms what?
  11. Which part of the neural tube becomes the brain?
    Cranial portion
  12. The brain arose from where?
    Cranial portion of the neural tube
  13. Which part of the neural tube becomes the spinal cord?
    Caudal portion
  14. The spinal cord arose from where?
    Caudal portion of the neural tube
  15. When does gastrulation occur?
    Day 15
  16. What happens in gastrulation?
    Cells of the epiblast migrate towards the primitive streak, then detach from epiblast and sneak beneath it to form mesoderm
  17. Major source of the nervous system tissue is from which layer?
  18. True/False: there is a subdivision of ectoderm called neuroectoderm?
  19. What gives rise to the nucleus propulsus?
  20. How is the neural plate formed?
    The notochord induces the overlying ectoderm to thicken into the neural plate
  21. What does the neural plate eventually becomes?
    Neural tube
  22. Outline the progression of neural tube formation
    Notochord -> neural plate -> neural tube
  23. What is neurulation?
    Folding f neural plate into a closed tube of ectoderm
  24. When does the neural plate form?
    Days 16-18, beginning the process of folding
  25. When does the lips of the neural folds make physical contact?
    Around day 22
  26. When does the cranial neuropore close?
    Around day 25
  27. When does the caudal neuropore close?
    Day 27
  28. What results from a closed neuroectoderm?
    Adult CNS structures form
  29. What results in anencephaly?
    Failure of cranial neuropore to close
  30. What characterizes anencephaly?
    Open defect in the skin with exposure of the cranial neural tube
  31. What is spina bifida?
    Most common neural tube defect as a result of neural tube malformation
  32. What characterizes spina bifida?
    Cleft in the vertebral column, most typically in the lumbar region
  33. What went wrong during folding that results in spina bifida?
    Caudal neuropore incomplete closure
  34. What is spina bifida occulta?
    Benign subtype of spina bifida, cleft in the vertebral column but without skin and neural structure defects
  35. What is spina bifida with meningocele?
    Sac containing the meninges pushes through the vertebral column
  36. What is a meningomyelocele in spinal bifida
    Sac contains meninges and neural tissue
  37. What is rachischisis?
    Complete spina bifida, cleft extend through the entire spine from the cervical region to the sacrum
  38. At week 4, which part of the neural tube becomes the forebrain?
  39. At week 4, which part of the neural tube becomes the midbrain?
  40. At week 4, which part of the neural tube becomes hindbrain?
  41. What are the two named bends called in week 4, and where are they located?
    • Cephalic flexure- midbrain
    • Cervical flexure- inferior border of the rhombencephalon
  42. At week 5, which primary vesicles subdivide and form secondary brain vesicles?
    Prosencephalon and rhombencephalon
  43. What do prosencephalon become at week 5?
    Telencephalon and diencephalon
  44. What do rhombencephalon become at week 5?
    Metencephalon and myelencephalon
  45. What does the telecephalon become?
    Cerebral hemisphere
  46. What does the diencephalon become?
    Thalamus, hypothalamus
  47. What does the mesencephalon become?
  48. What does the metencephalon become?
    Pons, cerebellum
  49. What does the myelencephalon become?
  50. What is the most caudal portion of the neural tube called?
  51. What does the myelon become?
    Spinal cord
  52. When does the brain develop its characteristic bumps and grooves?
    Later part of gestation, starting around 6 months
  53. Why do gyri and sulci develop?
    Later stages in development, as the brain expands it becomes folded in order to fit large piece of nervous tissue into the confines of the cranial cavity
  54. How big is the newborn brain relative to an adult brain?
    25% of the adult size
  55. Brain continues to grow as a result of what?
    Myelination of axons, begins in the third trimester and continues after birth
  56. What is the function of the ventricles?
    Produce CSF
  57. When do ventricles start to form?
    Week 5
  58. What happens to the skull when there is hydrocephalus?
    Increased intracranial pressure, expansion of the cranial vault, enlarge the head and thin the skull bones
  59. True/False: parts of the eye are CNS extensions
    True, optic nerve and neural retina
  60. Which is the innermost layer of the retina?
    Neural retina
  61. Which part of the retina contains photoreceptors?
    Neural retina
  62. How is the choroid fissure form?
    Invagination of the optic vesicle
  63. What is coloboma?
    An eye defect as a result of choroid fissure not closing during week 7
  64. What is the mantle layer?
    A region of the closed neural tube that produces neuroblasts
  65. What eventually becomes the gray matter of the spinal cord?
    Mantle layer
  66. What is the dorsal portion of the spinal cord called?
    Alar plate
  67. What is the ventral portion of the spinal cord called?
    Basal plate
  68. What is the function of the alar plate?
  69. What is the function of the basal plate?
    Motor region
  70. What does neural crest develops into?
  71. Where do neural crest cells derived from?
    Ectodermal cells
  72. What is DiGeorge Syndrome?
    Genetic deletion on Chromosome 22
  73. What is the clinical presentation of DiGeorge Syndrome?
    • Facial anomalies, cleft palate, congenital heart defects, problems with the immune system due to an underdeveloped thymus
    • Issues with guy and kidneys and parathyroid gland issues
  74. Where do neural crest cells arise from?
  75. True/False: preganglionic neurons are derived from neural crest
    False. POST-ganglionics are
  76. Where are prevertebral ganglia found?
    along the aorta
  77. What are examples of prevertebral ganglia
    Celiac, superior mesenteric
  78. Where are the postganglionic ganglia found?
    Sympathetic trunk ganglia
Card Set
Embryology Nervous System
NMSK Exam 3 Embryology Nervous System