1.2 Embryology Flashcards Preview

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Flashcards in 1.2 Embryology Deck (38):
1

What is the primitive streak?

3rd week

Initiates development of germ layers

2

What function does the notocord have in an adult?

None

3

What does the notocord do?

Induces neurulation

Converts OVERLYING ectoderm to NEUROECTODERM

4

How does the notocord arise?

gastrulation

5

What is gastrulation?

formation of the trilaminar embryo

6

What are the three embryo layers?

Ectoderm

Mesoderm

Endoderm

7

What are neuropores?

As the neural tube closes, it zips towards the cranial and caudal end

The openings at either end are neuropores

8

What does a caudal neural tube defect result in?

Spina bifida

9

What does a cranial neural tube defect result in?

Anencephaly

10

What is spina bifida?

Cleft spine

Failure of closure

11

Where does spina bifida usually occur?

Lumbosacral region

12

What two features will you see with spina bifida?

Hydrocephalus

Neurological defects

13

What is hydrocephalus?

Accumulation of CSF in the ventricular system

14

What is anencephaly?

Absence of cranial structures

Including brain

15

What is rachischisis caused by?

Failure of neural fold elevation

16

how would you test for Neural Tube defects?

Raised maternal serum alha-fetoprotein

17

What can a women consume in order to reduce the possibility of NTDs?

Folic acid

18

What does most of the neural tube develop into?

Spinal cord

19

What is at the end of the spinal cord?

Medullary cone

20

What happens after the 3rd month, when the spinal cord is the same length of the vertebral column?

The vertebral column keeps extending

Takes nerve roots with it

forms the CAUDA EQUINA

21

How is the brain first developed?

As three primary brain vesicles

22

What is the 2nd stage of brain development?

The three primary vesicles develop into 5 secondary brain vesicles

23

Why does the brain fold up as it develops?

Because it runs out of space linearly

24

What is the cervical flexure?

The spinal cord-hindbrain junction

25

What is the cephalic flexure?

Midbrain bend/fold

26

What is the role of the ventricles?

Cushion the brain and spinal cord

27

How is hydrocephalus treated?

Use a shunt

28

What do the roof and floor plates do in early neural tube development?

Regulate Dorsal and ventral patterning

29

What does the alar plate do?

Sensory

30

What does the basal plate do?

Motor

31

What does the neuroepithelial layer line?

The ventricular system

32

What is the sulcus limitans?

The junction between the dorsal and ventral halves during early neural tube development

33

What are the layers of the neural tube in early development? (Inside to out)

Neuroepithelial layer

Intermediate layer - neuroblasts

Marginal layer - processes

34

Where are neural crest cells found?

Lateral border of the neuroectoderm tube

35

What happens to neural crest cells?

Become displaced

enter mesoderm

Undergo epithelial to mesenchymal transition

36

What are some neural crest cell derivatives?

Cranial nerve ganglia
Dorsal root ganglia
Sympathetic ganglia
Parasympathetic ganglia

THINK GANGLIA

37

What is neural crest cell migration particularly susceptible to?

Alcohol

38

Name to types of neural crest migration conditions?

One structure - Hirschsprung's disease

Multiple structures - DiGeorge Syndrome