Development of the Nervous System Flashcards Preview

B - Embryology for EoY4 > Development of the Nervous System > Flashcards

Flashcards in Development of the Nervous System Deck (78)
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1

Over what time frame does the nervous system undergo development? 

It is the first system to begin development, and the last to complete development 

2

What does the early development of the nervous system reflect? 

The fact that its formation is a priority for the embryo 

3

What is meant by the nervous system being a very plastic system? 

It is changing all the time, even after birth 

4

What is the clinical relevance of the length of time it takes the nervous system to develop? 

It is most susceptible to insult during pre-natal development 

5

What effect does alcohol have on the developing nervous system? 

It disrupts communication between developing neurones 

6

What is the notocord? 

A solid cord of cells 

7

What is the notocord formed by? 

Prenotocordal cells migrating through the primitive pit 

8

What does the definitive notocord serve as? 

The baseline for the midline, axial skeleton, and neural tube 

9

What does the notocord release? 

Lots of diffusion limited signalling molecules 

10

What can the signalling molecules released by the notocord act on? 

Only cells that are close, and have the right receptor 

11

What is the result of interaction between the notocord and ectoderm? 

Formation of neuroectoderm 

12

What does the formation of neuroectoderm cause? 

The induction of the neural plate 

13

What happens to the neural plate in development? 

The lateral edges of the neural plate elevate, and the depressed midregion becomes the neural groove 

14

What happens to the neural folds during development? 

They gradually approach each other in the midline and fuse 

15

Where does fusion of the neural folds begin? 

In the future cervical region (in the middle), and then proceeds in both cranial and caudal directions 

16

What is produced by fusion of the neural folds? 

The neural tube 

17

By what stage in development is the neural tube completely closed? 

Day 28-32

18

What do neural tube defects result from? 

The failure of the neural tube to close 

19

What happens if failure of the neural tube to close occurs caudally? 

Gives spina bifida 

20

Where in the spinal cord does spina bifida occur? 

Can occur anywhere along the length, but most common in the lumbosacral region

21

What occurs with spina bifida? 

  • Neurological defects
  • Hydrocephalus nearly always 

 

22

Are the neurological defects in spina bifida associated with cognitive delay? 

No 

23

What is hydrocephalus? 

Accumulation of the CSF within the ventricular system 

24

What can hydrocephalus lead to? 

  • Brain impairments
  • Congitive delay 

 

25

What happens if failure of the neural tube to close occurs cranially? 

Anencephaly

26

What is anencephaly? 

Failure of formation of the head structures, including brain 

27

What is the prognosis of anencephaly? 

It is incompatible with life 

28

What is the most severe form of anencephaly? 

Rachischisis

29

What is rachischisis? 

Failure of neural fold elevation 

30

How can neural tube defects be deteted? 

  • Raised maternal serum alpha-fetoprotein 
  • USS