Cellular Injury

Question 1

What is a cellular adaptation?

Answer 1

-a reversible functional and structural response to a stress or stimulus

Question 2

What are 4 examples of cellular adaptation?

Answer 2

• hypertrophy
• hyperplasia
• Atrophy
• Metaplasia

**these are all reversible

Question 3

What is metaplasia?

Answer 3

• a change in a cell’s phenotype (adaptation)

e. g. metaplasia in airway of smokers

Question 4

What happens to a cell if a nefarious stimulus persists or is severe?

Answer 4

-the cells undergo irreversible injury and cell death

Question 5

What happens when a cell is continuously out of ATP?

Answer 5

-membrane injury:

• cellular constituents leak out of cell
• Ca2+ enters cell –> damage
• intracellular enzymes are released and activated

Question 6

(T/F) Membrane injury only involves the cell membrane.

Answer 6

F. it also involves the membranes of mitochondria and other organelles

Question 7

What happens when an injury causes a bunch of Ca ions to enter the cytosol of the cell?

Answer 7

Activates:

• ATPases
• Phospholipases
• Proteases
• Endonucleases

Question 8

How can free radicals damage cells?

Answer 8

• lipid peroxidation of cell membrane
• inactivates enzymes
• causes DNA damage

Question 9

With irreversible cell membrane injury which of the following will occur:

A. Influx of Na+ and Ca++
B. Influx of K+
C. Efflux of Na+
D. Efflux of Ca++

Answer 9

A. Influx of Na+ and Ca++

Question 10

What are Caspases?

Answer 10

Enzymes that lead to apoptosis.Two Types:

• Initiator: (8&9) activate execution caspases in conjunction with other proteins
• Executor: disrupt cytoskeleton and degrade DNA

Question 11

What is Bcl-2?

Answer 11

• part of a family of proteins that regulate cell growth
• ratio of members of family determines whether a cell will live or die
• affect mitochondrial permeability

Question 12

Which members of the Bcl-2 family favor apoptosis?

Answer 12

• Bax
• Bad
  others. ..

Question 13

Which members of the Bcl-2 family inhibit apoptosis?

Answer 13

• Bcl-2
• Bcl-XL
  others. ..

Question 14

Which of the following is characteristic of apoptosis:

A. Inflammation
B. Large numbers of cells affected
C. Internucleosomal DNA breaks
D. Free radical damage

Answer 14

C. Internucleosomal DNA breaks

Question 15

What is a Giemsa or Wright/Giemsa stain used on?

Answer 15

Blood smears

Question 16

What must be maintained for a cell to continue living?

Answer 16

• Cell membrane must remain intact
• Aerobic metabolism –> ATP must continue
• Protein synthesis must continue
• Nuclear DNA integrity must be maintained

Question 17

Is Cytochrome C associated with the intrinsic or extrinsic apoptosis pathway?

Answer 17

intrinsic

Question 18

Loss of Bcl-2 can be seen in what major process?

A.  inflammation
B.  injury
C.  repair
D.  hemodynamic disturbance
E.  neoplasia

Answer 18

E. Neoplasia

Question 19

What is the cellular morphology of apoptosis?

Answer 19

• cell shrinkage
• nuclear chromatin condensation
• formation of blebs = apoptotic bodies
• phagocytosis of apoptotic bodies

Question 20

What are the two features of a reversible cellular injury?

Answer 20

• Hydropic change (cellular swelling)

- Fatty change (Steatosis), increase in fat in cell due to interference w/ protein/fat metabolism

Question 21

What is a hydropic change?

Answer 21

-increased water in the cell due to the loss of the Na/K pump, cellular swelling

Question 22

What are the two types of irreversible cell injury?

Answer 22

• apoptosis

- Necrosis

Question 23

What are the three possible histological findings of a cell nucleus going through necrosis/apoptosis?

Answer 23

• Karyolysis = paler staining
• Pyknosis = shrunken, dark staining
• Karyorrhexis = fragmentation

Question 24

What happens histologically to a cell undergoing necrosis?

Answer 24

-the cytoplasm gets pinker

=an increase in eosinophilia

Question 25

What are the four patterns of Necrosis?

Answer 25

- Coagulative necrosis - Liquefactive necrosis (brain or abscess) - Caseous necrosis (tuberculosis or fungi) - Fat necrosis (pancreas most common, also mastitis)

Question 26

What are the microscopic features of coagulative necrosis?

Answer 26

- cell outline/border remains - more eosinophilic cytoplasm (redder) - cytoplasmic structures indistinct - nuclei absent

Question 27

What are the gross and microscopic features of liquefactive necrosis?

Answer 27

Gross: -soft, pus, fluid Microscopic: - no cell outlines remain - "empty" space with/without granular pink material

Question 28

What are the gross and microscopic features of caseous necrosis?

Answer 28

Gross: -caseous = soft, cheese-like material Microscopic: - +/- indistinct cell outlines - no nuclei - amorphous pink material

Question 29

What are the gross and microscopic features of Fat necrosis?

Answer 29

Gross: - maybe soft - areas of calcium deposits (gritty) Microscopic: - vague cell outlines may remain - no nuclei - +/- calcification (calcium + fat = saponification)

Question 30

What happens to cells in a hypertrophic heart?

Answer 30

-cells cannot get any larger then rupture and die

Question 31

What is the mechanism of atrophy?

Answer 31

- decreased protein synthesis | - usualy by ubiquitin-proteasome pathway

Question 32

What is the mechanism of metaplasia?

Answer 32

-reprogramming of existing normal stem cells or undifferentiated mesenchymal cells

Question 33

What is hemosiderin?

Answer 33

- a breakdown product of hemoglobin | - contains iron

Question 34

What is lipofuscin?

Answer 34

a "wear & tear" pigment from membrane damage

Question 35

What are the two types of calcification? What's the difference between them?

Answer 35

Dystrophic Calcification: -deposition of calcium in damaged tissues Metastatic Calcification: -calcium deposited in normal tissue (due to high serum calcium)

Question 36

What are Psammoma bodies?

Answer 36

- show up in ovarian tumors | - microscopic appearance of round laminated calcium nodules

Question 37

How do you histologically change hydropic change from fatty change?

Answer 37

- both will have large white cells - hydropic change cells still have nucleus in center - fatty change cells are more circular, nucleus is not in middle of white

Question 38

What type of necrosis is gangrene?

Answer 38

coagulative

Question 39

Caseous necrosis is associate with which of the following? A. TIssue ischemia B. Fatty change C. Pancreatitis D. Tuberculosis

Answer 39

D. Tuberculosis

Question 40

ENlargement of the thyroid gland because of increased levels of TSH is an example of: A. Hypertrophy B. Hyperplasia C. Metaplasia D. Atrophy

Answer 40

B. Hyperplasia **Hypertrophy mostly occurs in muscle

Question 41

WHat are the four naturally endogenous pigments?

Answer 41

- lipofuscin - Melanin - Hemosiderin - Bilirubin