Cell injury and death

Question 0

Common causes of reversible cellular injury

Answer 0

Trauma - concussion, frost bite
Hypoxia
Ischemia

Question 1

Hypoxia

Answer 1

decreased availability of oxygen - pneumonia or CO
loss of oxygen carrying capacity of the blood
Loss RBCs anemia
Brain (neurons) most sensitive

Question 2

Ischemia

Answer 2

insufficient blood supply
absence of oxygen AND nutrients
occlusion of an artery or vein

Question 3

common causes of irreversible cell injury

Answer 3

hypoxia - brain cells 
Ischemia - cardiac cells 
Physical agents - trauma 
Chemical agents - drug 
infectious agents 
immunologic reactions 
genetic disease 
nutritional disorders

Question 4

Apoptosis

Answer 4

cell has internal signal for death
programmed cell death
clean way to die and remove cell
No inflammation - prevents damage to adjacent cells

Question 5

Where is apoptosis commonly seen?

Answer 5

embryogenesis 
hormone induced changes 
mild trauma or injury removing nonfunctional cells 
chemo & radiotherapy - Neurons more resistant 
Immune reactions 
Atrophy 
Graft vs host disease 
some viral diseases

Question 7

Events of Apoptosis

Answer 7

cell becomes densely eosinophilic 
shrinks with pyknosis of nucleus 
cytoplasmic blebs 
phagocytosis of apoptoic bodies 
cell fragments

Question 8

What is the definition of pathology?

Answer 8

The study of disease

Question 9

What does it mean when a cell experiences hyperplasia?

Answer 9

Increase in the number of cells in any organ tissue

Question 10

What are the etiological reasons for cells to undergo hyperplasia?

Answer 10

Physiologic - hormone induced
Compensatory - callus formation
Pathologic - viral infection causing warts

Question 11

What does it mean when a cell undergoes hypertrophy?

Answer 11

Increase size of the cell or organ

Question 12

What is the parthenogenesis of hypertrophy?

Answer 12

Increased functional demand (running)
Hormonal stimulation (thyroxin)

Question 13

What does it mean when a cell experiences atrophy?

Answer 13

Shrinkage in the size of the cell by loss of structural components

Question 14

What could cause a cell to enter an atrophic state?

Answer 14

Dec workload
Loss of innervation
Diminished blood supply
Inadequate nutrition 
Loss of endocrine stimulation

Question 15

What does it mean when a cell undergoes metaplasia?

Answer 15

Reversible change in which one adult epithelial cell type is replaced by another adult type epithelium

Question 16

What could happen if there was a pathologic and prolonged irritation causing metaplasia?

Answer 16

Dysplasia which can lead to Cancer (squamous cell)

Question 17

What does it mean when a cell experiences dysplasia?

Answer 17

Epithelial or mesenchymal cells that have undergone metaplasia then atypical cytogical alterations involving cell size, shape and orientation

Question 18

What can dysplasia lead to?

Answer 18

Cancer (a neoplasia/uncontrolled growth)

Question 19

What is the chaperone ubiquitin-protease?

Answer 19

An intracellular accumulant which causes the cells to obtain a yellow tinge with aging

Question 20

What is antracosis?

Answer 20

Carbon pigment in the lung

inc in smokers

Question 21

What are some example of intracellular accumulations?

Answer 21

Lipofuscin
Melanin
Iron
Calcium
Fat
Bilirubin

Question 22

What is lipofuscin?

Answer 22

A yellow pigment that occurs both physiologically and pathologically that is left over from the breakdown and absorption of damaged blood cells
Likes the heart

Question 23

What causes an increase in melanin?

Answer 23

Tanning

Question 24

What does a bruise turn brown?

Answer 24

Due to iron deposition and hemosiderin

Question 25

What could cause an accumulation of bilirubin?

Answer 25

``` Bile duct occulsion Alcoholism Drugs Hemolytic anemia Pancreatic tumors ```

Question 26

What are the functions to regulate cell populations due to apoptosis?

Answer 26

``` Calcium sensitive endonuclease leading to pyknosis Transgluaminase activity causing cytoplasmic shrinkage by cross linking proteins Gene activation (bcl-2, c-myc, p53) ```

Question 27

What are the four factors that could lead to apoptosis?

Answer 27

Injury from radiation, toxins and free radicals Withdrawal of growth factors Receptor ligand interactions Cytotoxic T cells

Question 28

What are the steps to apoptosis?

Answer 28

``` Intrinsic embryogenic e Execute caspases Catabolism of cytoskeleton Apoptotic body with ligand receptors Ingested by macrophage ```

Question 29

What is nuclear pyknosis?

Answer 29

Ink-dot appearance that represents the first light microscopic evidence of cell death

Question 30

What is the normal pathway for apoptosis when viewed in a light microscope?

Answer 30

Pyknosis > karyorrhexis (fragments) > karyolysis (full breakdown)

Question 31

How is aging death by apoptosis?

Answer 31

Sub lethal cellular injury Programmed genetically by chromosome 1 induced telmoric shortening Limited number of cell division due to telomeres Renegade cells (cancer)

Question 32

What are the 4 forms of necrosis?

Answer 32

Coagulation, liquid, caseous and fat

Question 33

What does coagulative tissue look like?

Answer 33

Looks like the tissue was boiled Outline of cell preserved Seen in hypoxic death (except brain) Anucleate eosinophils

Question 34

What are the best examples of coagulative necrosis?

Answer 34

Kidney and myocardium

Question 35

What characterizes liquefactive necrosis?

Answer 35

Progressive degradation of cell by enzymes and denaturation of proteins either by autolysis or heterolysis Seen with fungal/bacterial infections

Question 36

Where is liquefactive necrosis often seen?

Answer 36

The brain

Question 37

What is fat necrosis?

Answer 37

Saponification of fat cells with calcification due to enzymatic breakdown of lipases Dystropic calcification

Question 38

Where does fat necrosis tend to occur?

Answer 38

Breast and liver | Can be seen along with cancer

Question 39

How is caseous necrosis characterized?

Answer 39

Distinct pattern of centralized amorphous debris and surrounding granulomas

Question 40

What is gangrenous necrosis?

Answer 40

Not a distinct pattern and happens to hypoxic limbs | Combo of coagulative (dry) and liquefactive necrosis

Question 41

What is fibrinoid necrosis?

Answer 41

Accumulation of amorphous, basic, proteinaceous material in the tissue matrix that stains like fibrin