Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

2 - MOD > deck_659289 > Flashcards

deck_659289 Flashcards

1
Q

How is cellular proliferation controlled?

A

– Hormones– Local mediators– Direct cell-cell or cell-stroma contact

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

What is autocrine signalling?

A

The cell secretes the growth factors which stimulate itself

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

What type of signalling is paracrine signalling?

A

The secreting cell and responding cell are different

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

Describe epidermal growth factor

A

– Mitogenic for epithelial cells, hepatocytes and fibroblasts– Produced by keratinocytes, macrophages and inflammatory cells– Binds to epidermal growth factor receptor (EGFR)

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

Describe Vascular endothelial growth factor and what it is involved in

A

Potent inducer of blood vessel development (vasculogenesis) and role in growth of new blood vessels (angiogenesis) in tumours, chronic inflammation and wound healing

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

Describe Platelet-derived growth factor

A

– Stored in platelet alpha granules and released on platelet activation– Also produced by macrophages, endothelial cells, smooth muscle cells and tumour cells– Causes migration and proliferation of fibroblasts, smooth muscle cells and monocytes

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

What are the final outcomes of signalling?

A

Survive (resist apoptosis)Divide (enter cell cycle)Differentiate Die (apoptosis)

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

By what methods does increased growth occur by?

A

By shortening the cell cycle and by conversion of quiescent cells to proliferating cells (convert G0 cells to G1 cells)

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

Define mitosis

A

nuclear division

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

Define cytokinesis

A

Cell division

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

Name the different phases in cell division

A

G1SG2MG0

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

What occurs in G1?

A

Gap oneIs pre synthetic and when the cell grows

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

What occurs in S phase?

A

DNA synthesis

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

What occurs in G2?

A

Gap 2Premitotic timeThe cell is preparing to divide

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

What is interphase made up of?

A

G1, S and G2

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

How is the cell cycle controlled?

A

Checkpoints which occur though the cycle

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

What are the checkpoints in the cell cycle?

A

G1 = after G1, before S phaseG2 = after G2, before M phaseRestriction point

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

Describe the R point

A

After this point, cells are not responsive to growth factors so division will take place. – Is the most commonly altered checkpoint in cycle in cancer cells

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

What does activation of R checkpoint do?

A

Delays cell cycle and triggers DNA repair mechanisms or apoptosis via p53

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

What regulates the progression through the cell cycle?

A

Cyclins and CDKs (cyclin dependent kinases)

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

How do cyclins and CDKs regulate the cell cycle?

A

Cyclins bind with CDKs to form an active complex. Activated CDKs phosphorylate proteins which are critical in cell cycle transitionsThis activity is tightly regulated

22
Q

How is cyclin production stimulated?

A

Growth factors

23
Q

What do stem cells power?

A

Proliferative capacity which replenishes the loss of differentiated cells.

24
Q

Describe the stem cells present in labile cell populations

A

Divide persistently to replenish losses

25
Describe the stem cells present in stable cell populations
Stem cells normally quiescent or proliferate very slowly, but proliferate persistently when required
26
Describe the stem cells present in permanent cell populations
Stem cells present, but cannot mount an effective proliferative response to significant cell loss.
27
Give some examples of labile cells
Surface epithelia e.g. epidermis, gut epitheliumBone marrow
28
Give some examples of stable cells
Liver hepatocytesBone osteoblasts
29
Give some examples of permanent cells
Brain neuronesCardiac and skeletal muscle
30
Define cell adaptation and state whether it is reversible or irreversible
the state between a normal unstressed cell and an overstressed injured cellIt is reversible
31
Define regeneration
Replacement of cell losses by identical cells to maintain tissue or organ size
32
What are the two outcomes of regeneration?
RESOLUTION -- The harmful agent is removed, tissue damage is limited and regeneration occursSCAR -- Harmful damage persists so extensive tissue damage occurs. Sometimes permanent cells.
33
Give some examples of regeneration
Hepatocytes can regenerate post lobectomySkin epidermis regenerates after burns
34
Define hyperplasia
Increase in tissue or organ size due to increased cell numbers
35
Describe some characteristics of hyperplasia
Is under physiological controlOnly occurs in stable or labile populationsCan occur secondary to a pathological cause NB -- multiple division expose the cell to increased risj of mutation and neoplasia
36
Give some physiological and pathological examples of hyperplasia
PHYSIOLOGICALEndometrium of uterus under influence of oestrogen Bone marrow produces more erythrocytes in response to hypoxiaPATHOLOGICALEczema -- thickened epidermisThyroid goitre in iodine deficiency
37
Define hypertrophy
Increase in tissue or organ size due to increased cell size
38
Where doe hypertrophy usually occur and what causes it?
In permanent cells as they cannot divide-- caused by increased functional demand or hormonal stimulation-- can occur alongside hyperplasia-- cells will contain more structural components
39
Give some physiological and pathological examples of hypertrophy
PHYSIOLOGICALSkeletal muscle in body buildersPregnant uterusPATHOLOGICALVentricular hypertrophy due to hypertenstion(RV hypertrophy is due to pulmonary hypertension)Bladder smooth muscle wall hypertrophy(due to obstruction and enlarged prostate gland)
40
Define atrophy
Shrinkage of a tissue or organ due to an acquired decrease in size and/or number of cells
41
What is organ or tissue atrophy usually due to?
a combination of cellular atrophy and apoptosis
42
Describe atrophy
Cellular atrophy = loss of cell sizeCell shrinks to a size at which survival is still possible -- there are reduced structural components of the cell. Is an adaptive response which may result in death.
43
Give a physiological example of atrophy
Ovarian atrophy in post menopausal women
44
What can pathological atrophy be due to?
-- Reduced functional demand/workload (muscle atrophy after disuse)-- denervation atrophy-- Inadequate blood supply (thinning of skin on legs with peripheral vascular disease)-- Inadequate nutrition (malnutrition)-- Loss of endocrine stimuli (breast, repro organs)-- Persistent injury (polymyostisis)-- Aging = senile atrophy (brain, heart)-- Pressure: tissues around growing benign tumour
45
Define metaplasia
Reversible change of one differentiated cell type to another cell type
46
Where can you generally see metaplasia?
In epithelial cells
47
Why can metaplasia occur?What can it lead to?
It may represent an adaptive substitution of cells that better adapted to a particular environment.Can lead to dysplasia and cancer
48
Give an example of metaplasia
SMOKERSBronchial pseudostratified ciliated epithelium --> stratified squamous epithelium due to effect of cigarette smokeBARRETT'S OESOPHAGUSStratified squamous epithelium --> gastric glandular epithelium with persistent acid reflux
49
Define aplasia
Complete failure of a specific tissue or organ to developIs an embryonic developmental disordere.g. thymic aplasia --> autoimmune and infections
50
Define hypoplasia
Underdevelopment or incomplete development of a tissue or organ at the embryonic stagee.g. kidneys, testes in Kilinefelters syndrome, chambers of the heart
51
Define dysplasia
Abnormal maturation of cells within a tissue which is potentially reversible. Often is pre-cancerous

2 - MOD (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions