9: Nervous system development

Question 1

When does the brain begin to develop?

Answer 1

3rd week

Question 2

What are two factors affecting brain development?

Answer 2

Genetics

Environment

Question 3

What is a metabolic disease which can cause developmental delay or regression?

Answer 3

PKU

Question 4

Exposure to what environmental factors can affect brain development?

Answer 4

Alcohol, drugs

Nutrition in general

Viruses, bacteria

Question 5

When is the embryonic period?

Answer 5

Conception to Week 9

Question 6

When is the foetal period?

Answer 6

Week 9 to Birth (on average Week 40)

Question 7

What are the two initial layers of an embryo?

Answer 7

Epiblast

Hypoblast

Question 8

Cells migrate through what to form the mesoderm?

Answer 8

Primitive streak

Question 9

What are the three layers remaining after cells have migrated through the primitive streak?

Answer 9

Epiderm

Mesoderm

Endoderm

Question 10

Which germ layer develops into bone, muscle, cartilage and the vascular system?

Answer 10

Mesoderm

Question 11

Which germ layer develops into the skin, hair, nails and nervous system?

Answer 11

Ectoderm

Question 12

Which germ layer forms the skin, hair, nails and neural tissue?

Answer 12

Ectoderm

Question 13

Which germ layer develops into the gut and respiratory system?

Answer 13

Endoderm

Question 14

Why is it significant that the skin, hair, nails and brain develop from the same germ layer?

Answer 14

Neurocutaneous diseases e.g NF

Question 15

What is the first neural structure to form?

Answer 15

Neural tube

Question 16

What disorders occur if the neural tube doesn’t close properly during development?

Answer 16

Neural tube defects e.g spina bifida, anencephaly

Question 17

What zone is found inside the neural tube?

What does the outside of the tube form?

Answer 17

Ventricular zone

Cerebral cortex, i.e the brain itself

Question 18

The caudal part of the neural tube forms what?

Answer 18

Spinal cord

Question 19

What is neural patterning?

Answer 19

Cells in the brain develop specific functions depending on their position

Question 20

When is the foetal period?

Answer 20

Week 9 till birth

Question 21

Why does the brain develop sulci and gyri?

Answer 21

Originally flat but needs to fit through birth canal, so folds to maximise surface area

Question 22

Neurones ___ and then ___.

Answer 22

divide

migrate

Question 23

Can neurons multiply once they have migrated?

Answer 23

No

Question 24

Neurons migrate from the ___ of the brain to the ___.

Answer 24

ventricles to cortex

Question 25

What are two types of process found in neurons which allow them to communicate with each other?

Answer 25

**Dendrites** **Axons** (much bigger)

Question 26

What percentage of neurons die off before birth?

Answer 26

**50%**

Question 27

If division and migration are the important processes of the prenatal period, what is the important process in the postnatal period?

Answer 27

**Myelination**

Question 28

What is myelin?

Answer 28

**Fatty substances which insulates axons** (allows nerve impulses to travel further and quicker)

Question 29

What directions does myelination occur in?

Answer 29

**Bottom to top** **Back to front**

Question 30

Apart from myelination, what is required for the brain to develop in the **postnatal period**?

Answer 30

**EXPERIENCE** i.e brain input

Question 31

In the postnatal period, a lack of **\_\_\_** deprives the brain of the input it needs to develop.

Answer 31

**experience**

Question 32

Brain development is ___ by positive inputs.

Answer 32

**enriched**

Question 33

What period of life is very important for brain development?

Answer 33

**Adolescence** | (10-19 years-ish)

Question 34

What process describes the loss of neurons which aren't used in order the maximise the efficiency of the brain?

Answer 34

**Synaptic pruning**

Question 35

Why do your emotions and brain function change so much during adolescence?

Answer 35

**Anatomical reorganisation**

Question 36

Supposedly... **oestrogen** makes girls (more / less) stressed **androgen** makes boys (more / less) stressed.

Answer 36

**oestrogen** - more **androgen** - less

Question 37

Are brain insults in the first weeks of gestation **compatible** **with life**?

Answer 37

**No - foetus will spontaneously abort**

Question 38

What embryological structure causes major disease if it doesn't form correctly?

Answer 38

**Neural tube**

Question 39

Name two neural tube defects.

Answer 39

**Anencephaly** (no brain) ## Footnote **Spina bifida**

Question 40

What process, important for development in the postnatal period, may be disordered?

Answer 40

**Myelination**

Question 41

What are three types of myelination disorder?

Answer 41

**Hypomyelination** (not enough) ## Footnote **Dysmyelination** **Demyelination**

Question 42

What dietary problem has a huge impact on brain development?

Answer 42

**Malnutrition**

Question 43

Malnutrition has an effect in which period of life?

Answer 43

**All of them** prenatal, postnatal, adolescence, adulthood, old age