021914 4 Neuroembryology 2 Flashcards Preview

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Flashcards in 021914 4 Neuroembryology 2 Deck (33):
1

Cause of craniorachischisis totalis?

total failure of neurulation

2

Cause of anencephaly?

failure of anterior neuropore closure

3

Cause of myeloschisis?

failure of posterior neuropore closure

4

Cause of encephalocele? What characteristic is observable?

partial failure of neurulation
occipital pouch containing clear fluid/neural tissue

5

Diastematomyelia is caused by: and how does it look?

persistence of neurenteric canal causes split spinal cord

6

Tethered spinal cord is caused by:
2

fixed caudal end (filum terminale) of spinal cord
persistence of neuroenteric canal

7

Sacral hypoplasia/hypoplastic (underdeveloped) femurs is characteristic of what syndrome?

Caudal regression syndrome

8

cerebral hemispheres remain fused
malformation of brain/face
cleft lips, single nostril, single eye
what syndrome?

holoprosencephaly

9

disorder of migration
smooth brain, few to no gyri
disorder?

lissencephaly (agyria)

10

disorder of migration
broad, few gyro
disorder?

pachygyri

11

disorder of migration
small gyri, normally sized brain disorder?

polygyri

12

disorder of migration
cleft brain (chunk missing)
disorder?

schizencephaly

13

failure of sclerotome cells to migrate into the region dorsal to the neural tube leading to the absence of vertebral arches in that region occurs in what disorder?

spina bifida occulta

14

Does spina bifida occulta involve neural tissue and show clinical symptoms?

no

15

Does spina bifida cysticA involve neural tissue and show clinical symptoms?

yes

16

What is meningocele?

fluid filled sac protrudes through defect (absence of vertebral arches)

17

What is myelomeningocele?

fluid filled sac protrudes through defect (absence of vertebral arches)
neural tissue is included in sac

18

What forms the notochord?

Midline axial mesoderm

19

How is the neural plate formed?

Notochord induces the overlying ectoderm to form the neural plate

20

What levels does primary neurulation occur at?

C1 to S2

21

What levels does secondary neurulation occur at?

S3 to coccyx

22

What type of neurulation involves columnarization of neural plate and rolling/folding?

primary

23

What type of neurulation involves mesenchymal condensation, medullary cord/neural rod, and epithelial transition/cavitation?

secondary

24

When does the anterior neurpore close? posterior?

day 25, day 27

25

folic acid deficiency (alcoholics, nutritional deficiency)
diabetes
antiepileptic drugs (valproate, carbamazepine)
previous pregnancy with NTD
hyperthermia (hot tubs)
risk factors for what?

neural tube defects

26

Which protein would increase in maternal serum and amniotic fluid in cases of a neural tube defect?

alpha-fetal protein

27

notochord secretes ______ which induces overlying ectoderm to differentiate into neuroectoderm

sonic hedgehog (Shh)

28

________ regulate anterior-posterior axis development and secondary neurulation.

homeobox genes

29

_____ and _____ gradients promote “dorsoventral differentiation” of spinal cord.

Shh (ventral aspect)
bone morphologic protein (BMP) (dorsal aspect)

30

Which cells give rise to neuroblasts in the developing spinal cord?

neuroepithelial cells

31

Which cells give rise to the astrocytes and oligodendroglia?

neural tube cells, such as radial glial cells

32

____ and ____ are disorders of neuronal proliferation.

macrencephaly and microcephaly

33

Name the derivates of the five secondary vesicles of the developing brain.
telencephalon: ____
diencephalon: ____
mesencephalon: ___
metencephalon: ____
myelencephalon: ____

telencephalon: cerebral hemispheres
diencephalon: thalamus/hypothalamus
mesencephalon: mid-brain
metencephalon: pons, cerebellum
myelencephalon: medulla