Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Vertebrate development > Cell interactions + movements > Flashcards

Cell interactions + movements Flashcards

1
Q

Morphogenesis

A

= generation of form

= origin and development of morphological characteristics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Cell adhesiveness

A

Animal cells adhere to one another + the ECM

- via interactions involving cell-surface proteins known as adhesion molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Cell shape changes

A

Cells can actively change shape by means of internal contractions + constrictions

  • caused by cytoskeletal rearrangements
  • crucial in development processes e.g. folding of cell sheet
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Cell motility

A

Ability of cells to move as individuals or groups from 1 location to another

  • crucial to development
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

2 groups of embryonic cells

A

Epithelial cells
= sheet of cells joined to it’s neighbour by cell-cell adhesion

Mesenchymal cells
= scattered cells, embedded in loose ECM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

3 germ layers

A

Ectoderm

Mesoderm

Endoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When do 3 germ layers form?

A

Gastrulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which germ layers are epithelial and mesenchymal cells found in?

A

Epithelial = all 3 germ layers

Mesenchymal = ectoderm + mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Epithelia

- composition

A

Cells organised into sheets or tubules

- attached to an underlying basement membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Mesenchyme

- composition

A

Scattered cells surrounded by loose ECM

Little/ no contact with adjacent cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Mesenchyme

- role

A

Fills up much of the embryo

Later forms fibroblasts, adipose tissue, smooth muscle + skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Epithelia

- held together by..?

A

Cell junctions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Cell junctions

A

Specialised site on a cell at which it is attached to another cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

2 types of cell junction

A

Apical = cell-cell

Basal = cell-matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What polarity do epithelia have?

A

Apical-basal polarity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Apical interactions

- what do they both involve?

A

Cadherins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Apical interactions

- what are the 2 types?

A

Adherens junction

Desmosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Adherens junction

- composition

A

Actin filaments

Cadherin

Alpha-catenin
Beta-catenin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Desmosome

- composition

A

Intermediate filaments

Cadherin

Plakoglobin
Desmoplakin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Basal interactions

- what do the both involve?

A

Integrins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Basal interactions

- what are the 2 types?

A

Focal adhesion

Hemidesmosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Focal adhesion

- composition

A

Actin filaments

Integrin

Focal adhesion kinase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Hemidesmosome

A

Intermediate filaments

Integrin

Dystonin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Cadherins

- what are they?

A

Calcium-dependent transmembrane proteins

Protrude from cell

In presence of Ca2+
-> cadherins on adjacent cells stick together in zipper-like fashion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Cadherins

- in adherens junctions

A

Cadherins linked to intracellular proteins called catenins

-> catenins link to actin cytoskeleton

26
Q

Cadherins

- in desmosomes

A

Cadherins linked to intracellular proteins called plakoglobin

-> plakoglobin connected to intermediate filament proteins e.g. keratin

27
Q

Adheren junctions + desmosomes

- where are they present?

A

Adheren junctions
- many tissues

Desmosomes
- epithelia

28
Q

Immunoglobin-like adhesion molecules

A

e.g. N-CAM
= neural cell-adhesion molecule

Some mediate homophilic binding

Other = heterophilic
- bind to integrins

29
Q

Integrins

- what are they?

A

Proteins found in ECM

Protrude from cell

Bind to matrix proteins
- e.g. collagen

Have 2 subunits
- alpha + beta

30
Q

Integrins

- in focal adhesions

A

Focal Adhesion Kinase (FAK) links integrins to actin cytoskeleton

31
Q

Integrins

- in heme-desmosomes

A

Dystonin links integrins to intermediate filaments

32
Q

Apical junctions

- role

A

Mechanical links al cells within epithelial sheet

33
Q

Basal junctions

- role

A

Allow integrins to transmit info about ECM to cell

Signals can affect cell shape, motility, differentiation + metabolism

34
Q

3 key cellular properties required for morphogenesis

A

Cell adhesiveness

Cell shape change

Cell motility

35
Q

What happens when pieces of late ectoderm + endoderm from amphibian blastula are placed together?

A

Initially fuse to form smooth sphere

-> then separate until only a narrow bridge of tissue connecting the 2 together is left

36
Q

What happens when early ectoderm and mesoderm are placed together?

Why is this?

A

(normally adhere to one another)

Tissues don’t separate

  • instead the 2 pieces of tissue remain in contact
  • > mesoderm envelops ectoderm

They express complementary adhesion molecules so can interact with one another

37
Q

How is cell adhesiveness involved in cell sorting?

A

Differential adhesiveness
- due to differences in types + no.s of adhesion molecules on their surfaces

Cadherins = cell-type specific

Mix 2 cells expressing different cadherins or different amounts of same cadherin
-> organise themselves into like

38
Q

Changes in cell adhesiveness

- example

A

Ectoderm + mesoderm from amphibian blastulas are disaggregated into single cells when treated with alkaline solution

When cells are mixed together
-> sort out with mesoderm cells on outside

39
Q

Changes in cell shape

A

Generated by constrictions + contractions of cytoskeleton

40
Q

Cytoskeleton

- 3 principal types of protein polymers

A

Actin filaments

Microtubules

Intermediate filaments

41
Q

Actin filaments + microtubules

  • features
A

Dynamic structures

Polymerising + depolymerising according to the cell’s requirements

42
Q

Intermediate filaments

A

More stable

Forms rope-like structures that:
> transmit mechanical forces
> spread mechanical stress
> provide mechanical stability to cell

43
Q

Cell shape

- what can actin filaments assemble with?

A

Myosin
- into contractile structures
= act as miniature muscles

44
Q

Cell shape

- cleaving cell

A

Bundles of actin-myosin form a contractile ring

  • contraction of bundle pinches cell in 2
45
Q

Cell shape

- apical constriction

A

Contraction of ring of actin myosin ring around apical end
-> leads to apical constriction + elongation of cell

(volume of cell doesn’t;t charge)

46
Q

Cell shape

- migrating cell

A

Embryonic cells move by migration
- requires cell shape change

Cells extend lamellipodium
-> pushed outwards from cell by assembly of actin filaments

Contraction of actin myosin assembly at front of cell draws cell forward

47
Q

Cell motility

A
  1. Cell makes several attachments to ECM
  2. Actin rearrangements allow cell to send out lamellipodia at leading edge
    - > makes new attachments with substratum

= cell is stretching + cytoskeleton is under tension

  1. De-adhesion at rear end of cell releases tension
  2. Whole cell moves forward
48
Q

Which 2 factors does cell motility involve?

A

Changes in cell adhesiveness + cell shape

49
Q

What kind of morphogenetic processes underlie diverse forms of embryos?

A 
>Involution + invagination
>Cavitation
> Epithelial-to-mesenchymal transition
> Convergent extension 
> Epiboly 
> Delamination + ingression
50
Q

Involution + invagination

- generates?

A

Multi-layered structures from a simple epithelium

- can create hollow ball or tube

51
Q

Involution + invagination

- process

A

Arise due to changes in cell shape caused by contraction of cytoskeletal filaments

Localised contraction in actomyosin filaments in a few cells

All cells are mechanically linked
-> whole sheet drawn in at point of contraction

52
Q

Involution

- example

A

Gastrulation in Xenopus

Cells in marginal zone undergo apical constriction of cytoskeletal network
-> elongate
-> draws sheet in
= involutes

Caused by signalling molecules:
>BMPs
>Wnt

53
Q

Cavitation

- what is it?

A

Formation of a hollow ball or tube

54
Q

Cavitation
- process

  • example
A

Occurs through fluid filling or apoptosis of cells in a solid mass

e.g. blastocyst formation
- vectorial transport of fluid creates a cavity
= Blastocoele

55
Q

Cavitation

- example

A

Mammalian blastocyst formation

Blastocoele formed when sodium ions are actively pumped across basolateral surface of outer layer of trophectoderm cells

Blastocoele inflates as water moves in via osmosis
- prevented from escaping by tight junctions in apical regions

-> hydrostatic pressure
= gives blastocyst its spherical shape

56
Q

EMT (epithelial-to-mesenchymal transition) and ingression

- what is it?

A

Conversion of an epithelium into a more loosely connected mass of mesenchyme
OR into individual mesenchymal cells that can migrate

57
Q

EMT and ingression

- what does it involve?

A

Dissolution of adherens junction between epithelial cells

Migration of cells out of an epithelium

58
Q

MET (mesenchymal-to-epithelial transition)

A

Results in polarisation of motile cells

Establishes cell-cell contacts through formation of adherens junctions

Creates an organised epithelium

59
Q

Convergent extension

- what is it?

A

Sheet of cells changes shape due to active rearrangement of cells

60
Q

Convergent extension

- process

A

Axes defined

Cells become elongated in direction at 90 degrees to anterior-posterior direction

Cells become aligned parallel to one another in direction perpendicular to direction of tissue extension

Each end of bipolar cells from filopodia
- allows them to exert traction of neighbouring cells

61
Q

Epiboly

A

Expansion of sheet of cells to surround + enclose another population

Cells spread + thin out

Involves several changes:
cell division, alteration in cell shape + intercalation of cells

62
Q

Epiboly

- example

A

Gastrulation in fish

Spreading + thinning of ectodermal sheet
- expands over inner layers + eventually encloses them

Vertebrate development (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions