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Flashcards in Cellular adaptation Deck (74)
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1

What is cellular adaptation?

Mechanisms which allow tissues and organs to cope with changes in demand. They may be part of an entirely normal (physiological) process or occur as part of a disease (pathological) process

2

Are cellular adaptations usually reversible?

yes

3

Give the 5 things that can alter in cellular adaptation, why do these alterations occur?

1) Size
2) Number
3) Phenotype
4) Metabolic activity
5) Function
Occur due to changes in environment or demand

4

What is the role of cellular adaptation? 3

1) Aquire a new and steady state of metabolism and structure
2) Better equips cells to survive in a new environment
3) Failure of adaptation may lead to lethal or sub-lethal injury

5

Give an example of cell which is very susceptible to damage?

Cerebral neurons

6

Give an example of cell which is very resistant to damage?

Fibroblast

7

Name a type of cell which does not need to adapt in the face of environmental change and why?

Fibroblasts - can survive severe metabolic stress without harm eg. absence of O2

8

Name a type of cell which adapts easily to environmental change and why?

Epithelial cells
Labile cell population, have an active stem cell compartment
Highly adaptive in number and function

9

Name a type of cell which cannot adapt and why?

Cerebral neurons
Terminally differentiated
Permanent cell population
Highly specialised function
Easily damaged by environment change

10

What is meant by physiological cellular adaptation?

A cell responding to normal changes in physiology or demand

11

What is meant by pathological cellular adaptation?

A cell responding to disease related changes

12

What cellular adaptation occurs in response to increased cellular activity?

Increased size or number of cells

13

What cellular adaptation occurs in response to decreased cellular activity?

Decreased size or number of cells

14

What is the scientific term for increase in size of cells?

Hypertrophy

15

What is the scientific term for increase in number of cells?

Hyperplasia

16

Can hypertrophy and hyperplasia co-exist?

Yes

17

The net result of hypertrophy/hyperplasia is what?

Increased cell mass and thus increase in functional capacity

18

What kind of cell populations is hypertrophy commonly seen in, give an example?

Permanent cell populations
Especially cardiac and skeletal muscle

19

Give a physiological example of smooth muscle hypertrophy?

Hypertrophy of the smooth muscle cells of the uterus during pregnancy

20

Give a pathological example of muscle hypertrophy?

Hypertrophy of bladder muscle cells in benign prostatic hyperplasia - this leads to bladder outlet obstruction, bladder has to contract harder, so muscle becomes hypertrophied

21

Give an example of pathological hyperplasia?

Adenomyomatous hyperplasia of the prostate

22

Give a physiological example of skeletal muscle hypertrophy?

Skeletal muscle of a marathon runner

23

Give an example of pathological cardiac muscle hypertrophy?

Hypertrophy of cardiac muscle cells of left ventricle due to calcific aortic stenosis
This can also occur in systemic hypertension

24

Why can left ventricular hypertrophy lead to death?

Patients with LVH have increased ectopic beats, some of which can pre-dispose to sudden degeneration of rhythm to ventricular tachychardia or VF and sudden cardiac death

25

What is subcellular hypertrophy and hyperplasia, give an example?

Increase in size and number of subcellular organelles
For example, smooth ER hypertrophy in hepatocytes with barbiturates

26

What consequence can SER hypertrophy in hepatocytes with barbiturates lead to?

Increase in P450 mixed function oxidases which causes increased metabolism of other drugs - thus inactivating them

27

What 2 type of cell populations is hyperplasia possible in?

Labile and stable cell populations

28

For which 2 broad reasons may cell populations undergo physiological hyperplasia?

In response to hormones
As a compensatory mechanism

29

For which 2 broad reasons may cell populations undergo pathological hyperplasia?

Due to excess hormones or growth factors

30

Gynaecomastia is an example of what kind of cellular adaptation?

Pathological hyperplasia of the glandular and stromal tissue of the breast
Can be related to drugs and pathology elsewhere such as cirrhosis of the liver