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Flashcards in BRAIN DEVELOPMENT Deck (41)
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1

how does the neural tube form?

- in 3rd week ectoderm thickens in the mid-line to form neural plate
- it then undergoes mitosis to form neural groove
- the groove deepens and eventually detaches from the overlying ectoderm to form neural tube

2

what are neural crest cells found?

they lie lateral to the neural plate
they run dorsolaterally along the neural groove

3

what do neural crest cells form?

sensory ganglia
schwann cells
adrenal medulla
meninges
dermis

4

by which week have the prosencephalon, mesencephalon and rhombencephalon formed?

by week 5

5

what happens in week 5 of brain development?

proencephalon, mesencephalon and rhombencephalon developed

6

what happens in week 7 of brain development?

secondary brain vesicles have developed

7

what do the secondary brain vesicles develop into?

they give rise to the mature brain

8

what secondary vesicles does the prosencephalon give rise to?

telencephalon
diencephalon

9

what secondary vesicles does the mesencephalon give rise to?

mesencephalon

10

what secondary vesicles does the rhombencephalon give rise to?

metencephalon
myelencephalon

11

what mature brain structures are derived from the prosencephalon?

cerebral hemispheres
lateral ventricles
thalamus
hypothalamus
3rd ventricle

12

what mature brain structures are derived from the mesencephalon?

midbrain
aqueduct

13

what mature brain structures are derived from the rhombencephalon?

cerebellum
pons
upper 4th ventricle
medulla oblongata

14

what brain developmental milestone occurs at 3 weeks?

eye formation

15

what brain developmental milestone occurs at 10 weeks?

cerebral expansion and commissures

16

what brain developmental milestone occurs at 3 months?

basic structures

17

what brain developmental milestone occurs at 5 months?

myelination has begun

18

what brain developmental milestone occurs at 7 months?

lobes and cerebrum have formed

19

what brain developmental milestone occurs at 9 months?

gyri and sulci have formed

20

what is the type of CNS abnormality dependent on?

the time of infection

21

what are the critical periods for developing CNS abdnormalities?

week 6 = eye malformations
week 9 = deafness
week 5-10 = cardiac malformation

22

when do CNS abnormalities tend to occur?

in the 2nd trimester

23

when does risk of CNS abnormalities decrease, why?

after 16 weeks
this is because most structures have developed by this point

24

when should the neural tube be closed by?

by the end of week 4

25

what is spina bifida?

failure of closure of the neural tube in spinal region

26

what is anencephalus?

failure of closure of the neural tube in the cephalic region

27

how can you detect brain activity?

lumbar puncture
EEG
monitor haemodynamic activity

28

how can you use a lumbar puncture to measure brain activity?

increased neural activity results in increased release of neurotransmitters and their breakdown products
this is measured in CSF from lumbar punctures

29

how do EEGs detect brain activity?

they give indication of regional brain activity
they are useful for detecting signs of epilepsy
over-excitation of neurons can lead to cell death

30

how can you detect brain activity through haemodynamic monitoring?

more neurally active regions require more oxygen and blood
this technique measures changes