Cellular Injury and Adaptation (P)

Question 1

*What are the mechanisms of cell injury?

Question 2

What are the causes of injury?

Answer 2

1) Hypoxia
2) Chemicals and drugs
3) Physical agents
4) Microbiologic agents
5) Immunologic rxns
6) Genetic defects
7) Nutritional imbalances
8) Aging

Question 3

*What are the targets of injurious stimuli?

Answer 3

(all *)

1) Aerobic respiration
2) Integrity of cell membranes
3) Protein synthesis
4) Cytoskeletal system
5) Integrity of the genetic apparatus of the cell

Question 4

*Principles and concepts

Question 5

What are the causes of atrophy?

Answer 5

1) Decreased workload
2) Loss of innervation
3) Diminished blood supply
4) Inadequate nutrition
5) Loss of endocrine stimulation
6) Aging

Question 6

Atrophy results from what?

Answer 6

It results from decreased protein synthesis and increased protein degradation

Question 7

What is the function of ubiquitin-proteasome pathway?

Answer 7

It activates ubiquitin ligases

Question 8

What is the characteristic of ubiquitin-proteasome pathway?

Answer 8

Accelerated proteolysis

Question 9

What is the characteristic of atrophy?

Answer 9

It is accompanied by increased autophagy

Question 10

What are the causes of hypertrophy?

Answer 10

1) Physiologic
     A. Hormonal
          -> estrogen stimulation of uterus in pregnancy
     B. Compensatory
2) Pathologic 
     A. Excessive hormonal stimulation
     B. Viral-induced

Question 11

*What is the characteristic of hypertrophy?

Answer 11

*It involves signals

Question 12

*What are the 2 triggers that involves signals?

Answer 12

(all *)

1) Mechanical triggers
2) Trophic triggers

Question 13

What are signal transduction pathways and its purpose?

Answer 13

*These are the induction of genes that stimulate protein

Question 14

*Growth factors

Question 14

*Growth factors

Question 15

What are the causes of hyperplasia?

Answer 15

1) Physiologic
     A. Hormonal 
          -> estrogen stimulation of uterus
     B. Compensatory
2) Pathologic
     A. Excessive hormonal stimulation 
     B. Viral-induced

Question 16

What are the causes of metaplasia?

Answer 16

1) Persistent irritation
2) Infection
3) Malnutrition

Question 17

What is deranged development (under dysplasia)?

Answer 17

1) It is the proliferation and atypical cytologic alterations
2) It is the change in size, shape, and organization

Question 18

What is the characteristic of dysplasia?

Answer 18

It is not an adaptive mechanism but a change for the worse

Question 19

What are the exs of reversible injury?

Answer 19

1) Cellular swelling

2) Fatty change

Question 20

*What is the characteristic of necrosis?

Answer 20

It is a form of irreversible injury

Question 21

What is necrosis?

Answer 21

It is the sum of all the morphologic changes that follow after cell death

Question 22

What are the types of necrosis?

Answer 22

1) Liquefaction necrosis
2) Coagulative necrosis
3) Enzymatic fat necrosis
4) Caseous necrosis
5) Gangrenous necrosis

Question 23

Liquefaction necrosis results from what?

Answer 23

It results from the action of powerful hydrolytic enzymes

Question 24

What are the characteristics of liquefaction necrosis?

Answer 24

1) It is best exemplified by brain infarction 2) It is brought about by ischemic destruction of brain tissue 3) It is a form of common "pus", abscess

Question 25

Coagulative necrosis results from what?

Answer 25

It results from the total occlusion of supplying vessels especially in solid organs

Question 26

*The total occlusion of supplying vessels especially in solid organs (in coagulative necrosis) results to what?

Answer 26

1) Conversion of the cell to acidophilic tombstone 2) Loss of nucleus but cell architecture preserved 3) Protein denaturation (precipitation) 4) Exemplified by myocardial infarction

Question 27

What is enzymatic fat necrosis?

Answer 27

It is the destruction of fat resulting from abnormal release of enzymes especially lipases

Question 28

*The principle of action that destruction of fat results from abnormal release of enzymes especially lipases is an ex of what?

Answer 28

*Acute pancreatitis

Question 29

What is the principle of action of saponification?

Answer 29

The action of lipase on fat results in dissolution together w/ hydroxyl ions (-OH) will produce soap w/ addition of Ca will result in formation of "chalky" mat

Question 30

What is caseous necrosis?

Answer 30

It is the combination of liquefaction and coagulative necrosis

Question 31

What are the characteristics of caseous necrosis?

Answer 31

1) It is only seen in tuberculosis process | 2) It has a characteristic "cheesy appearance"

Question 32

What is gangrenous necrosis?

Answer 32

It is the combination of liquefaction and coagulative necrosis

Question 33

What are the 2 types of gangrenous necrosis?

Answer 33

1) Dry | 2) Wet

Question 34

The classification of gangrenous necrosis regarding on what type is it classified in depends on what?

Answer 34

It depends on the predominance of necrosis

Question 35

Provide an ex of dry (type of gangrenous necrosis)

Answer 35

Gangrene of the foot due to diabetes

Question 36

Provide an ex of wet (type of gangrenous necrosis)

Answer 36

Gangrene of loose organs (e.g. appendix)

Question 37

What is apoptosis?

Answer 37

1) It is a tightly intracellular program whereby cells destined to die activate enzymes that degrade the cell's own nuclear DNA and nucleo-cytoplasmic protein 2) Programmed cell death

Question 38

What are the mechanisms of apoptosis in physiologic situations?

Answer 38

1) Programmed destruction of cells during embryogenesis 2) Hormone-dependent involution in aging 3) Cell deletion in proliferating cell populations 4) Death of host cells that have served its purpose 5) Elimination of potentially harmful self-reactive lymphocytes 6) Cell death induced by cytotoxic T cells

Question 39

*What are the characteristics of intracellular accumulations?

Answer 39

1) Increased production w/ N metabolism 2) Lack of enzymes for endogenous by-products of metabolism 3) Exogenous substance not metabolized because of absence of enzymes