L02: Development And Anomalies Of Development Of CNS

Question 1

Between which days does the first neurone become born in pre-natal period

Answer 1

22-26days

Question 2

What does it mean if the first neurones are born in 22-26 days

Answer 2

Mother doesn’t realise she is pregnant at this stage (22-26days) so environmental factors can affect the embryo

Question 3

Does a just born infant have a fully developed brain

Answer 3

No

Question 4

At 12 months (post natal) what is the state of profileration

Answer 4

Majority of proliferation is complete but not all neurones are born.
It is only the majority.

Question 5

Why is the first 3 years of postnatal period important

Answer 5

Neurone form circuits via synapses

Question 6

At what age is the brain mature in gross structures

Answer 6

20 years

Question 7

Does development of the brain continue after 20 years

Answer 7

Yes

Question 8

What are the 3 layers of cells in gastrulation

Answer 8

Endoderm
Mesoderm
Ectoderm

Question 9

What does the endoderm form in the neonate

Answer 9

Viscera

Question 10

What does the mesoderm form in the neonate

Answer 10

Musculoskeletal system

Question 11

What does the ectoderm form in the neonate

Answer 11

Nervous system

Question 12

What are the 3 layers/regions of the ectoderm

Answer 12

Epidermis
Neural plate border
Neural plate

Question 13

Why does one part of the ectoderm from the neural plate

Answer 13

Physical cell to cell interaction when cell surface protein in that area allow the neural plate to form
Extracellular secreted molecules that come from the mesoderm and notochord to induce the ectoderm to from the neural plate

Question 14

What is neuralation

Answer 14

Physical changes that occur in the ectoderm

Question 15

As a result of neuralation what structures are formed in the ectoderm

Answer 15

Neural grove of the neural plate

Neural folds of the neural plate border

Question 16

After neuralation what happens to the neural folds

Answer 16

Neural folds fuse together to from the neural crest and neural tube

Question 17

What does the neural tube form

Answer 17

The CNS i.e spinal cord and brain

Question 18

What does the neural crest form

Answer 18

The cells bodies within the PNS

Question 19

What can occur if there is a defective closure of the neural tube anteriorly

Answer 19

Anencephaly

Question 20

What is anencephaly

Answer 20

A baby born with no or limited brain

Question 21

What happens if there is a defect in the close of the neural tube posteriorly

Answer 21

Spina bifida

Question 22

What are the causes of neural tube closure defects

Answer 22

• Problem of cell division that is dependent on folic acid

- gene defects that affect cell to cell interactions

Question 23

What happens to the neural tube that form the brain

Answer 23

Has swellings that represent the forebrain, midbrain and hindbrain.

Question 24

What determines cells if they are anterior or posterior

Answer 24

Anterior posterior patterning

Question 25

What is anterior-posterior patterning

Answer 25

Signals that determine whether cells are anterior or posterior

Question 26

What signals tell the cell they are anterior to the brain

Answer 26

Signals secreted on cell surface

Question 27

Name an example of a cell surface signal that signals to anterior of brain

Answer 27

Dickkopt

Question 28

What signalling molecule are the anterior signals dependent on

Answer 28

Retinoic acid

Question 29

What is retinoic acid

Answer 29

A derivative of Vitamin A

Question 30

If a pregnant women takes EXCESS vitamin A what can happens to the anterior signalling

Answer 30

Interfere with the anterior signalling

Question 31

What is dorsal- ventral patterning

Answer 31

Signalling molecule which produce a protein in the ventral part of the developing brain to get cells to dorsal or ventral part

Question 32

What does the motor neurone in the ventral brain form

Answer 32

Cranial nerves

Question 33

What other neurones are found in the ventral brain

Answer 33

Dopaminergic neurones | Serotenergic neurones

Question 34

What does the grey matter of the cortex contain

Answer 34

Cell bodies

Question 35

What occurs in the grey matter of the cortex to organise neurones during development

Answer 35

1) proliferation 2) migration 3) differentiation

Question 36

Where does proliferation occur

Answer 36

Ventricular zone

Question 37

What does proliferation in the ventricular zone result in

Answer 37

New neurones being formed

Question 38

What happens to the baby neurones in the ventricles after they have been produced

Answer 38

Migrated

Question 39

For migration to occur what is required

Answer 39

A signal

Question 40

What structure forms a scaffold for migrating cells in the developing cortex for cells in the ventricular zone

Answer 40

Radial glia

Question 41

How far does the neurones migrate up the radial glia

Answer 41

Not far only just up the ventricular zone

Question 42

What happens to the ventricular zone as time moves on

Answer 42

Produce more and more new neurones

Question 43

How far does the next batch of new neurones travel up the radial glia

Answer 43

More far than the first batch of neurones

Question 44

What is the process of forming the inside layer first and then the outer layer called

Answer 44

Inside out layering

Question 45

What abnormalities can occur if migration doesn’t work properly

Answer 45

Cortical dysgenesis

Question 46

What is cortical dysgenesis

Answer 46

Cortex not forming properly

Question 47

When does differentiation occur

Answer 47

When the neurones reach their final destination

Question 48

What causes transmitter and ion channels to the neurones during differentiation

Answer 48

Differential gene activation

Question 49

How do axons extern and grow to correct targets

Answer 49

At the tip of the axon a specialised region known as the growth cone tastes its environment of chemoattractant and repellents so it finds its right way

Question 50

What is fascilation

Answer 50

When axons grow in bundles

Question 51

What does fascilation cause the production of

Answer 51

White matter tracts in the brain

Question 52

After the axon has founds it right way via growth cones how does it form synapses

Answer 52

With a 2 way signalling process

Question 53

What is a 2 way signalling process

Answer 53

When the pre-synaptic neurone and post-synaptic neurone interact with neutrophic factors

Question 54

How can actual neurones be lost

Answer 54

Necrosis and apoptosis

Question 55

Name an example of a dorsal ventral signalling molecule

Answer 55

Sonic hedgehog

Question 56

Name an example of a cortical dysgenesis

Answer 56

Lissencephaly

Question 57

What is lissencephaly

Answer 57

Smooth cortex