Neuro 3 - Development of the Nervous System

Question 1

What is the name given to the proliferation of the ectoderm in the dorsal midline?

Answer 1

Neural plate

Question 2

What happens to the neural plate as it thickens?

Answer 2

folds up on the sides and eventually the two neural folds fuse to form a tube

Space in the middle = neural canal

Question 3

What is the name given to the bunch of cells at the tip of the neural fold that are excluded in the fusion?

Answer 3

Neural crest

Question 4

Which cells do the neural tube and the neural crest give rise to?

Answer 4

Neural Tube = all CNS cells

Neural Crest = all PNS cells

Question 5

What is the name given to the wall of the neural tube?

Answer 5

Neuroepithelium

Question 6

What three types of cells do neuroepithelium give rise to?

Answer 6

Neuroblasts
Glioblasts
Ependymal cells

Question 7

Are motor neurons produced from the neuroepithelium?

Answer 7

Yes

Question 8

State 4 types of cells that neural crest cells can differentiate into?

Answer 8

Sensory neurons of dorsal root ganglia and cranial ganglia
Autonmoic post ganglionic neurons
Schwann Cells
melanocytes

Question 9

Describe the arrangement of the neuroepithelium.

Answer 9

inner and outer layer

most cells connected to both inner and outer layers

Question 10

Describe the differentiation of the neuroepithelium.

Answer 10

Cells withdraw from outer membrane towards inner membrane

undergoes mitosis

one of the daughter cells will remain attached to inner membrane

other daughter cell will move away from inner membrane and become a neuroblast

Question 11

What are the three layers formed by the differentiation of the neuroepithelium?

Answer 11

ependymal, grey matter, white matter

Question 12

Can glioblast migrate into the white matter?

Answer 12

Yes

Question 13

What guides the process of differentiation and migration?

Answer 13

Signalling molecules

Question 14

What factors are important with regards to signalling molecules?

Answer 14

concentration and timing

Question 15

What can the grey matter of the neural tube be divided into?

Answer 15

alar and basal plates

Question 16

Which types of neurones do the alar and basal plates give rise to?

Answer 16

alar - interneurons

basal - interneurons and motor neurons

Question 17

Which structures around the neural tube release signalling molecules?

Answer 17

Notochord and ectoderm

Question 18

Around 4 weeks, you get differentiation of the wall of the anterior neural tube to form three primary vesicles. Name these primary vesicles.

Answer 18

Prosencephalon – future forebrain
Mesencephalon – future midbrain
Rhombencephalon – future hindbrain

Question 19

Describe the changes that occur to the three vesicles in the week following their formation.

Answer 19

First and third divide into 2

Question 20

What important structure begins to appear quite late in development and where does it appear?>

Answer 20

Cerebellum - pounching out of the pons

Question 21

Name the 3 flexures in the developing brain?

Answer 21

Cephalic, Pontine, Cervical

Question 22

Describe the formation of the 4th ventricle.

Answer 22

the space left from the proliferation of the roof plate will become the 4th ventricle

Question 23

Describe the arrangement of motor, sensory, autonomic cranial nuclei within the brainstem.

Answer 23

motor - medial
sensory - later
autonomic - in between

Question 24

What structure divided the motor and sensory nuclei in the brainstem?

Answer 24

Sulcus limitans

Question 25

How do neuroblasts migrate from the inner membrane ot the outer membrane in the brain?

Answer 25

attach to radial glial cells and climb up

Question 26

What happens to neuroblasts that stay in the middle of the cortex

Answer 26

become basal ganglia

Question 27

How many layers are there in the cerebral cortex?

Answer 27

6

Question 28

What can a deficiency of folic acid in pregnancy lead to?

Answer 28

spina bifida