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Flashcards in Embryology: developmental processes Deck (29)
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1

what is the first differentiation event?

blastocyst forming

2

what is the driving force behind the first lineage restriction?

polarisation

3

what are the two domains of polarisation?

-apical domain
-basolateral domain

4

what part of the blastocyst becomes polar and what does not?

Trophoblast cells become polarised, while the Inner Cell Mass cells lack apical/basal polarity

5

what is polarisation?

formation of apical complex

6

what is asymmetric cell divison?

segregation of apical complex

7

what is cell position?

suppression of apical complex in inner cells

8

what is cell fate?

restricted expression of lineage specific genes

9

what are signalling centres?

the node/organiser

10

what does the node/organiser do?

Produces signalling molecules that direct the development of surrounding tissues

11

what can transplants of node/organiser induce?

the formation of a second body axis and neural tube

12

where are organisers found?

all vertebrate embryos

13

what happens when the primitive node swelling produces signals?

signal diffuses away and encounters other cells, those cells will respond to signal in specific way, this response will be different between cells types i.e one signal has a range of effects

14

Describe the signalling gradients.

Positional information: cells respond in a specific way depending on the concentration of the signalling molecule

15

what does signalling gradients regulate?

Differentiation in the Neural Tube by providing Positional Information

16

what does noto cord produce?

signal molecule sonic hedgehog will diffuse up through neural tube

17

where does BMP's signal molecule diffuse?

dorsal regions forwards

18

what is it called when there is equal number of sonic and BMP signals?

interneurons

19

what does programmed cell death help?

shape the embryo

20

How are digits of feet and hands formed?

BMP4 signalling triggers cell death programme in the interdigital zones of foot and hand plate

21

what do localised changes in shape during neurulation lead to?

folding of the neural plate at median and doors-lateral hinge points

22

where does tissue fusion occur?

the edges of the neural plate are brought together

23

what is tissue fusion also required for?

formation of the face

24

how are structures of the face formed?

5 facial swellings fuse

25

describe cell migration.

Movement of cells from one location to another is a frequent event during development:
-Gastrulation
-Neural Crest
-Germ Cells
-Interneurons

26

Describe the epithelial to mesenchymal transition (EMT).

Epithelial Cell State: cells arranged in a sheet with specialised membrane contacts; adherens and tight junctions

Mesenchymal Cell State: loosely associated, often motile cells with only transient focal attachements to other cells

27

what are transitions between these states required for?

> Gastrulation
> Neural Crest
> Cardiac Valves
> Secondary Palate formation

28

what are E-Cadherins?

the ‘caretaker’ of the epithelial cell state

29

what are 90% of oral cancers characterised by?

low E-Cadherin expression.
Salvia appears to provide a good environment for metastasis