Embryo

Question 1

What is the critical pre-natal period for brain development?

Answer 1

12 weeks -18 weeks

Question 2

What happens if the mother is exposed to teratogens after the prenatal critical period?

Answer 2

since brain development continues after gestation(postnatally), this can cause intellectual,emotional and behavioral disabilities

Question 3

When are the three germ layers formed?

Answer 3

during gastrulation (16 day)

Question 4

Ectoderm layer?

Answer 4

(outside layer) generates the skin and the nervous tissue

Question 5

Mesoderm layer?

Answer 5

(middle layer) generates most of the muscle, blood, connective tissue of the body and placenta

Question 6

Endoderm layer?

Answer 6

(inside layer) generates epithelial lining and associated glands of the gut,lung and uro-genital tracts

Question 7

Notochord will develop into …..

Answer 7

spinal cord and nervous tissue

Question 8

Notochord releases diffusible factors called….

Answer 8

morphogens(which signal molecules that form gradients and trigger gene expression)

Question 9

What happens when the ectoderm is exposed to BMP-4(coming from endoderm and mesoderm)?

Answer 9

ectoderm develops into the skin

Question 10

What are BMP-4 antagaonists that the node secretes?

Answer 10

noggin,chordin and follistatin

Question 11

What do the BMP-4 antagonists do ?

Answer 11

allow ectoderm to develop into nerve tissue and neural plate

Question 12

What is neurulation?

Answer 12

-folding and closing of the neural plate
-developing of the somite

Question 13

Where does the folding and closure of the neural tube occurs first?

Answer 13

at the cervical region

Question 14

When the neural tube zips, it leaves to opening known as …..

Answer 14

anterior and posterios neuropores

Question 15

At what day does the anterior neuropore closes?

Answer 15

day 25

Question 16

At what day does the posterior neuropore closes?

Answer 16

day 28

Question 17

Ancephaly?

Answer 17

-fetus doesn’t have closure of the anterior pore(doesn’t give rise to brain tissue)
-have massive retardation
-some die in vitro or through spontaneous abortion

Question 18

Spina bifida?

Answer 18

-fetus posterior pore doesn’t close (spinal cord doesn’t form properly)
-mostly in the lumbar region
-CSF is exposed to complications like infections or having nerve roots exposed

Question 19

Neural tube ventral side …

Answer 19

motor

Question 20

Neural tube dorsal side…

Answer 20

sensory

Question 21

BMP from skin induce expression of BMPs in roof plate which largely patterns….

Answer 21

alar plate

Question 22

SHH from the notochord induces expression of SHH in floor plate which largely patterns…

Answer 22

basal plate

Question 23

Neural crest cells down regulate….?

Answer 23

cadherin expression and delaminate

Question 24

neural crest cells transform from epithelial cells into….?

Answer 24

migratory mesenchymal cells that will contribute to forming many tissues in the body

Question 25

Neural crest derivatives originate from four major segments of the neurotaxis?

Answer 25

1. cranial
   2.cardiac
   3.vagal
   4.trunk & sacral

Question 26

Cranial neural crest gives rise to….

Answer 26

head connective tissue and skeletal structures(majority), nerves and pigment cells

Question 27

What are the 3 parts of the neural tube?

Answer 27

1.Prosencephalon (forebrain)
2. Mesencephalon (midbrain)
3. Rhomencephalon (hindbrain)

Question 28

Prosencephalon divides into?

Answer 28

telencephalon and diecephalon

Question 29

Rhombencephalon divides into?

Answer 29

metencephalon and myelencephalon

Question 30

What does telencephalon develop into?

Answer 30

paleocortex, corpus striatum, neocortex, hypothalamus,infundibulum

Question 31

What does diencephalon develop into?

Answer 31

Epithalamus, and thalamus

Question 32

What does Mesencephalon develop into?

Answer 32

tectum,tegmentum, cerebral peduncles

Question 33

What does Metencephalon develop into?

Answer 33

cerebellum and pons

Question 34

What does myelencephalon develop into?

Answer 34

medulla