how cells respond to injury

Question 1

What is hypertrophy?

Answer 1

increase in cell size

Question 2

What is hyperplasia?

Answer 2

increase in cell number

Question 3

What is metaplasia?

Answer 3

change of a tissue into another in response to a change in environment

Question 4

What are the ways a tissue can grow?

Answer 4

• multiplicative
• auxetic
• accretionary

Question 5

What is multiplicative growth of tissue?

Answer 5

increase in cell number by mitotic division

Question 6

What is auxetic growth of tissue?

Answer 6

increase in cell size

Question 7

What is accretionary growth of tissue?

Answer 7

increase in extracellular tissue

Question 8

What are the ways cells can respond to stress?

Answer 8

• adapt
• suffer reversible injury
• suffer irreversible injury
• die

Question 9

What are the 4 options cells have to adapt?

Answer 9

• hypertrophy
• hyperplasia
• atrophy
• metaplasia

Question 10

What is atrophy?

Answer 10

reduction in cell size and/or number

Question 11

What is starvation?

Answer 11

atrophy of an entire organism

Question 12

How is growth calculated?

Answer 12

increase in cell number - decrease

Question 13

What adaptive response is available to permanent cells?

Answer 13

only hypertrophy

Question 14

What are the 3 types of cells when it comes to proliferation?

Answer 14

• labile cells
• stable cells
• permanent cells

Question 15

Describe the proliferation, cell turnover and lifespan of labile cells

Answer 15

• continuous proliferation
• high cell turnover
• short lifespan

Question 16

Describe the proliferation, cell turnover and lifespan of stable cells

Answer 16

• good regeneration ability
• low cell turnover
• longer lifespan

Question 17

Describe the proliferation, cell turnover and lifespan of permanent cells

Answer 17

• little/no regeneration
• very low/no cell turnover
• long lifespan

Question 18

Give examples of labile cells

Answer 18

• epithelial cells
• white blood cells

Question 19

Give examples of stable cells

Answer 19

hepatocytes (liver cells)

Question 20

Give examples of permanent cells

Answer 20

• neurons
• cardiac/skeletal muscle
• red blood cells

Question 21

What is an example of physiological hypertrophy?

Answer 21

hypertrophy of skeletal muscle through training

Question 22

What is an example of pathological hypertrophy?

Answer 22

cardiac hypertrophy owing to hypertension/valvular disease

Question 23

What are the two types of physiological hyperplasia?

Answer 23

• hormonal
• compensatory

Question 24

What is hormonal physiological hyperplasia?

Answer 24

hyperplasia that increase the functional capacity

Question 25

What is compensatory hyperplasia?

Answer 25

hyperplasia when tissue is lost

Question 26

What is pathological hyperplasia often due to?

Answer 26

usually excess hormonal stimulation of cells

Question 27

How is pathological hyperplasia distinct from neoplasia?

Answer 27

because if the stress influence goes away, the cells go back to normal

Question 28

In what tissues is metaplasia commonly seen?

Answer 28

- usually in epithelium - possible in mesenchymal tissues

Question 29

Explain the mechanism behind metaplasia?

Answer 29

stem cell differentiate along a different pathway owing to a change in the local microenvironment

Question 30

Describe smoking's involvement in metaplasia

Answer 30

bronchial ciliated epithelium to stratified squamous epithelium

Question 31

Describe the sort of cycle that happens with reversible cell injury?

Answer 31

1. changes in ion conc means changes in osmosis 2. swelling of cell means changes in organelles and cytoskeleton 3. increasing eosinophilia and redness

Question 32

At what point does reversible cell injury become irreversible cell injury

Answer 32

when lysosome ruptures and autodigestion starts

Question 33

What are the 3 nuclear changes that can happen because of irreversible cell injury

Answer 33

- karyolysis - karyorrhexis - pyknosis

Question 34

What is karyolysis?

Answer 34

breakdown of nucleus because of enzymes released by lysosome

Question 35

What is karyorrhexis?

Answer 35

rupture of nuclear membrane

Question 36

What is pyknosis?

Answer 36

process of nuclear shrinkage

Question 37

What is the mechanism of necrosis?

Answer 37

- mitochondrial damage - influx of calcium - accumulation of oxygen radicals - increased membrane permeability - DNA and protein damage - drop in pH (lactic acid)

Question 38

What are the 3 macroscopic patterns of necrosis

Answer 38

- coagulative - liquefactive/colliquative - caseous necrosis

Question 39

Describe coagulative necrosis

Answer 39

shape preserved for some time

Question 40

Describe liquefactive/colliquative necrosis

Answer 40

shape quickly lost

Question 41

Describe caseous necrosis

Answer 41

cheese-like appearance

Question 42

What are the two pathways for apoptosis?

Answer 42

1. death receptor mediated 2. mitochondrial mediated

Question 43

What is the final mechanism for apoptosis no matter the pathway?

Answer 43

activation of intracellular caspase 3 to degrade DNA and cell proteins

Question 44

What is the estimated human cell turnover?

Answer 44

a million a second