Development of the CNS

Question 1

When does neurulation begin

Answer 1

Week 4

Question 2

Where does the neural tube initially come from

Answer 2

5th somite

Question 3

When does the cranial neuropore close

Answer 3

25 days

Question 4

When does the caudal neuropore close

Answer 4

27 days

Question 5

Where does the spinal cord develop

Answer 5

caudal to 4th pair of somites

Question 6

What happens to the wall of the neural tube

Answer 6

Lateral walls thicken, reducing the size of the neural canal until only a central canal exists.

Question 7

What is the neural tube composed of

Answer 7

pseudostratified, columnar epithelium

Question 8

What are the three layers of the neural tube

Answer 8

ventricular zone
intermediate zone
marginal zone

Question 9

What cells are in the neuroepithelial zone

Answer 9

neuroepithelial cells closes to lumen, divide and migrate

Question 10

What cells are in the intermediate zone

Answer 10

cells differentiate into neurons/glia

Question 11

What cells are in the marginal zone

Answer 11

decreased cell bodies, contains axon that will be myelinated

Question 12

What happens if there is a failure of site 1 closure

Answer 12

spina bifida cystica

Question 13

what happens if site 2 doesn’t close

Answer 13

meroencephaly (anencephaly)

Question 14

What happens is sites 1, 2, and 4 don’t close

Answer 14

cranioachischisis

Question 15

How is site five closed

Answer 15

secondary neurulation

Question 16

What causes SB occulta

Answer 16

unfused neural arch

Question 17

What happens in SB with meningocele

Answer 17

meninges extrude

Question 18

What happens with SB w/meningomyelocele

Answer 18

meninges and neural tissue extends

Question 19

What happens with SB w/myeloschesis

Answer 19

open neural tissue

Question 20

Where do glioblasts form from

Answer 20

differentiate from neuroepithelial cells

Question 21

What do glioblasts become

Answer 21

astrocytes and oligodendrocytes

Question 22

What do glial cells turn into

Answer 22

ependymal cells

Question 23

what are microglia cells derived from

Answer 23

mesenchyme

Question 24

What controls proliferation and patterning of neuroepithelial cells

Answer 24

SHH

Question 25

What do cells in the alar plates form

Answer 25

dorsal gray columns, make kafferent nuclei and form dorsal gray horns

Question 26

What do cell bodies in the basal plates form

Answer 26

ventral and lateral gray columns

Question 27

What type of nuclei are formed in basal plates

Answer 27

efferent nuclei, make ventral gray and lateral gray horns

Question 28

What is the ventral median septum

Answer 28

As basal plates enlarge, form a bulge ventrally on each side

Question 29

What is the ventral median fissure

Answer 29

deep longitudinal groove formed on teh ventral surface of the ventral median septum

Question 30

What functions do the basal columns have

Answer 30

motor functions