embryology of the CNS and congenital malformations

Question 1

what happens in the third week?

Answer 1

formation of the primitive groove and pit in the embryonic ectoderm

Question 2

tuberous disorders

Answer 2

non-cancerous tumors ( subcorticol)

• seizures can occur

Question 3

what does the notochord do?

Answer 3

• provides signals necessary for development of CNS

- contributes to the invertebral discs

Question 4

sacrococcygeal teratoma

Answer 4

• failure of regression of primitive streak

Question 5

chordoma

Answer 5

ventral aspect of skull base

• residual of notochord tissue
• most benign but some can be malignant

Question 6

neuraltion

Answer 6

• neural plate thickens and folds into a tube

Question 7

neural tube forms the

Answer 7

CNS

Question 8

neural crest forms the

Answer 8

PNS and ANS

Question 9

Anencephaly

Answer 9

failure of neural tube closure

• end of the neural- cephalic issues; no brain

Question 10

mild thoracic myelomeningocele

Answer 10

failure of neural tube closure

• spinal cord herniates as well as meninges

Question 11

Lumbar myelocele

Answer 11

failure of neural tube closure

• spinal cord

Question 12

what creates gradients in cell patterning

Answer 12

morphogens and transcription factors

Question 13

concentration of morphogens creates

Answer 13

local signaling centers that helps guide cells to their correct position and to influence them into differentiation and specialization

Question 14

Holoprosencephaly

Answer 14

underexpression of ventralizing/dorsalizing gradients genes

Question 15

alobar Holo

Answer 15

ventral underexpression

• poor prognosis
• midline facial dysformities

Question 16

Lobar Holo

Answer 16

ventral underexpression

• benign course

Question 17

septo-optic dysplasia

Answer 17

dorsal underexpression

• pituitary disfunction
• some SE with vision due to nerve impingment

Question 18

prosencephalon

Answer 18

forebrain

Question 19

mesencephalon

Answer 19

midbrain

Question 20

rhombencephalon

Answer 20

hindbrain

Question 21

neuroblast goes on to form the

Answer 21

neurons

Question 22

glioblast goes on to form

Answer 22

astrocytes

Question 23

proliferating cells will populate the

Answer 23

concentric zones in neural tube

Question 24

ependymal cells goes on to form

Answer 24

microglial cells

Question 25

which one forms first?

• glioblast
• ependymal
• neuroblast

Answer 25

neuroblasts > glioblasts > ependymal

Question 26

selective pruning occurs via

Answer 26

apoptosis

Question 27

colossal agenesis

can be associated with what?

Answer 27

failure of the formation of the corpus collosum

• can be associated with a lipoma

Question 28

cells of the brain form

Answer 28

centrally and then migrate to the periphery

Question 29

subventricular zone

Answer 29

germ matrix layer (central layer where cells first form)

Question 30

cortical plate

Answer 30

post-mitotic cells which have migrated from the subventricular zone

• periphery

Question 31

malformation of the development of the cortex

Answer 31

1. neuronal/glial proliferation and apoptosis
2. neuronal migration
3. neuronal cortical organization

Question 32

lissencephaly

Answer 32

incomplete sulcation

• abnormal incomplete proliferation of neurons and glial cells

Question 33

subependymal nodular heterotopia

Answer 33

• grey matter that did not migrate out to the periphery

- increased risk of headaches

Question 34

polymicrogyria

Answer 34

thick cortex

• black tenticles
• increased number of gyri and they fuse

Question 35

myelin sheath forms

Answer 35

late fetal period

Question 36

developmen of myelin continues into

Answer 36

3 yrs of life (myelin is dark)

Question 37

x-linked adrenoleukodystrophy

Answer 37

abnormal myelination

• understand the pattern of myelination

Question 38

understanding the pattern of myelination can help us understand the

Answer 38

timing of injury

Question 39

congenital CMV

Answer 39

infection timing can affect differently

Question 40

congenital aqueductal stenosis

Answer 40

• fluid between ventricles are not flowing normally

Question 41

neural crest cells forms

Answer 41

dorsal root and other parts of the spinal cord

Question 42

thickened filum terminale

Answer 42

associated with a tethered cord

• spina bifida

Question 43

dermal sinus tract

Answer 43

development of the meninges/dura to the skin

prone to develop infections

Question 44

diastematomyelia

Answer 44

split cord malformation