Cellular Response to Stress and Toxic insult

Question 1

Define Hypertrophy

Answer 1

increase in the size of cells

Question 2

In regards to hypertrophy, as the size of cells increases, what is going on inside the cell?

Answer 2

increase in protein synthesis and in the size or number of intracellular organelles

Question 3

Define hyperplasia

Answer 3

increase in the number of cells

Question 4

This is the failure of cell production.

Answer 4

aplasia

Question 5

During fetal development, aplasia results in what?

Answer 5

agenesis, or absence of an organ due to failure of production

Question 6

This is a decrease in cell production that is less extreme than aplasia

Answer 6

hypoplasia

Question 7

What syndromes is hypoplasia seen in?

Answer 7

Turner and Klinefelter syndromes - partial lack of growth and maturation of gonadal structures

Question 8

This is a decrease in the size of an organ or tissue and results from a decrease in the mass of preexisting cells

Answer 8

atrophy

Question 9

What are the most common causes of atrophy?

Answer 9

disuse, nutritional or oxygen deprivation, diminished endocrine stimulation, aging, and denervation

Question 10

Define Metaplasia

Answer 10

replacement of one differentiated tissue by another

Question 11

Ischemia, anemia, carbon monoxide poisoning, decreased perfusion, poor oxygenation are all what types of cell injury?

Answer 11

hypoxic

Question 12

Describe the sequence of events that occurs in the early stage of hypoxic cell injury

Answer 12

1. decreased oxidative phosphorylation and ATP production by mitochondria
2. failure of the cell membrane pump (intracellular Na+ increase, intracellular K+ decrease)
3. cellular swelling - disaggregation of ribosomes
4. stimulation of PFK activity = increased glycolysis, decreased intracellular pH
5. clumping of nuclear chromatin

Question 13

Describe what occurs in the late stage of hypoxic cell injury

Answer 13

membrane damage to plasma and lysosomal and organelle membranes with a loss of membrane phospholipids

Question 14

What are two morphologic signs of hypoxic cell damage seen in the late stage?

Answer 14

myelin figures, cell blebs

Question 15

Intracellular enzymes such as glutathione peroxidase, catalase, and superoxide dismutase 2 do what?

Answer 15

degrade free radicals

Question 16

Which vitamins are capable of degrading free radicals?

Answer 16

A, C, and E

Question 17

What are some of the pathologic effects of ROS production?

Answer 17

membrane damage, protein misfolding, mutations

Question 18

In regards to hypoxic cell injury, what does the resultant increase in cytosolic Ca2+ cause?

Answer 18

activation of cellular enzymes like proteases, phospholipases - membrane damage; endonucleases - nuclear damage, and ATPase - decrease in ATP

Question 19

This is the sum of the degradative and inflammatory reactions occurring after tissue death caused by injury; it occurs within living organisms

Answer 19

necrosis

Question 20

The following describes what type of necrosis:
ischemia, particular the heart and kidney; general preservation of tissue architecture; increased cytoplasmic eosinophilia

Answer 20

coagulative necrosis

Question 21

The following describes what type of necrosis:

ischemic injury to the CNS (autolytic); suppurative infections characterized by the formation of pus (heterolytic)

Answer 21

liquefactive necrosis

Question 22

The following describes what type of necrosis:
occurs as part of granulomatous inflammation; seen with tuberculosis; combination of coagulative and liquefactive necrosis; amorphous eosinophilic appearance

Answer 22

caseous necrosis

Question 23

The following describes what type of necrosis:

lower extremities or bowel and is secondary to vascular occlusion; wet gangrene; dry gangrene

Answer 23

gangrenous necrosis

Question 24

The following describes what type of necrosis:

often associated with immune-mediated vascular damage

Answer 24

fibrinoid necrosis

Question 25

Is fat necrosis possible?

Answer 25

yes

Question 26

Define apoptosis

Answer 26

programmed cell death

Question 27

Describe the sequence of apoptosis starting from normal cell to apoptotic bodies

Answer 27

1. normal cell
2. cell shrinkage, chromatin condensing
3. membrane blebbing
4. nuclear collapse, continued blebbing
5. apoptotic body formation
6. lysis of apoptotic bodies

Question 28

True or false, apoptosis induces an inflammatory response.

Answer 28

false - no inflammatory response

Question 29

Describe the Extrinsic pathway of apoptosis

Answer 29

1. FAS ligand binds FAS
2. Activation of caspases
3. cascade of caspases leads to terminal caspases-3 and 6

Question 30

Describe the Intrinsic pathway of apoptosis

Answer 30

1. lack of survival signals (growth factor)
2. loss of bcd-2 (anti-apoptotic protein) from inner mitochondrial membrane
3. increased mitochondrial permeability - release of cyt c
4. stimulation of proapoptotic proteins bax and bak
5. cyt c interacts with Apaf-1 causing self-cleavage and activation of caspase-9 - apoptosis

Question 31

Describe how a cytotoxic T-cell induces apoptosis

Answer 31

1. perforin makes pore in cell membrane
2. granzyme B directly activates caspases
3. apoptosis