Cellular Adaptation; Injury and Death

Question 1

What are the 4 major types of adaptation?

Answer 1

Hypertrophy, Hyperplasia, Metaplasia, Atrophy

Question 2

What is Hypertrophy?

Answer 2

Increase in cell size

Question 3

What is Hyperplasia?

Answer 3

Increase in cell number

Question 4

What is Atrophy?

Answer 4

Decrease in cell size

Question 5

What is Metaplasia?

Answer 5

Change from one mature cell type to another

Question 6

Are adaptations reversible or irreversible?

Answer 6

Reversible changes

Question 7

What does cellular adaptation reflect?

Answer 7

Dynamic ability of cells to alter their cell cycle activity

Question 8

What is found in high amounts of cells undergoing hypertrophy?

Answer 8

RNA for increased protein synthesis

Question 9

What is decreased in atrophying cells?

Answer 9

Oxygen, protein levels, nutrients

Question 10

What are common causes of atrophy?

Answer 10

Disuse, denervation (loss of nerve supply), ischemia, poor nutrition, reduced endocrine stimulation

Question 11

What is an example of metaplasia in the esophagus?

Answer 11

Barrett metaplasia; increased exposure to gastric acid in the lower end of the esophagus forces squamous epithelium to change into columnar goblet cells

Question 12

What happens in metaplasia if the injurious stimulus continues?

Answer 12

Dysplasia occurs (pre-neoplastic change)

Question 13

What are the 7 causes of cell injury?

Answer 13

Hypoxia, Physical agents/mechanical forces, Chemicals/drugs, Infectious agents, Immunologic reactions, Genetic mutations/derangements, Nutritional imbalances

Question 14

What is hypoxia?

Answer 14

Diminished oxygen delivery

Question 15

What is ischemia?

Answer 15

Impaired blood flow

Question 16

Is hypoxia or ischemia worse and why?

Answer 16

Ischemia because it is decreased oxygen flow and nutrients

Question 17

What are the four major underlying mechanisms of cell injury?

Answer 17

Oxidative phosphorylation (decreased ATP)
ROS
Calcium homeostasis
Cell membranes

Question 18

What are reversible changes in cell injury?

Answer 18

Cell swelling (hydropic swelling) 
Fatty Change (accumulation of lipid vacuoles)

Question 19

What is ischemia reperfusion injury?

Answer 19

Damage done to the tissue once normal blood flow returns to it

Question 20

How might ischemia reperfusion injury occur?

Answer 20

Generating ROS

Some inflammatory mechanisms

Question 21

What happens in necrosis?

Answer 21

The cell swells and spills out its contains which recruits inflammatory cells and causing swelling

Question 22

What happens in apoptosis?

Answer 22

The cell is packaged up into pieces when dying and shrinks; no leakage of enzymes

Question 23

What are the four primary types of necrosis?

Answer 23

Coagulative, liquefactive, caseous, fat necrosis

Question 24

Morphology of coagulative necrosis?

Answer 24

Preserves basic cell outline and tissue architecture; cytoplasm shrinks and proteins coagulate due to acidic pH

Question 25

What are the three nuclear changes in coagulative necrosis?

Answer 25

Pyknosis Karyolysis Karyorrhexsis

Question 26

What is pyknosis?

Answer 26

Nuclear shrinkage and darkening

Question 27

What is karyolysis?

Answer 27

Nuclear dissolution

Question 28

What is karyorrhexsis?

Answer 28

Fragmentation of pyknotic nucleus

Question 29

What is liquefactive necrosis?

Answer 29

Complete enzymatic digestion of dead cells; pus (dead inflammatory cells); Tissue architecture is lost

Question 30

Where does liquefactive necrosis mainly occur?

Answer 30

CNS

Question 31

What can cause liquefactive necrosis?

Answer 31

Bacterial and fungal infections (abscess)

Question 32

What is gross and microscopic appearance of caseous necrosis?

Answer 32

Gross- cheesy white yellow and crumbly | Microscopic- amorphous granular pink material; no tissue architecture

Question 33

What is fat necrosis?

Answer 33

Destruction of adipocytes within fatty tissue

Question 34

What happens in acute pancreatitis?

Answer 34

Enzymatic digestion from lipases leaked into adipose tissue

Question 35

What can occur with large scale fat necrosis?

Answer 35

Saponification with the deposition of calcium salts in the tissue

Question 36

What are the two types of gangrenous necrosis?

Answer 36

Dry and wet gangrene

Question 37

What is dry gangrene?

Answer 37

Coagulative necrosis of tissues secondary to profound ischemia

Question 38

What is wet gangrene?

Answer 38

Liquefactive necrosis from inflammatory necrosis superimposed on ischemic necrosis. Usually secondary to bacterial infections at site of ischemic damage.

Question 39

What are the two major pathways of apoptosis?

Answer 39

Intrinsic and Extrinsic

Question 40

What is the cause of intrinsic apoptosis?

Answer 40

Injury: radiation, toxins, ROS free radicals, withdrawal of growth factors

Question 41

What is the cause of extrinsic apoptosis?

Answer 41

Death receptors: Fas and FasL TNRF1 and TNF ligand | Granzyme B

Question 42

What is the common mechanism for apoptosis?

Answer 42

The execution pathway: caspase enzyme cascade

Question 43

What are two stimuli in the intrinsic apoptosis pathway?

Answer 43

p53 tumor suppression activation | Pro-apoptotic members of Bcl family: Bax Bak

Question 44

What is steatosis?

Answer 44

Fatty acid accumulation in the liver

Question 45

What is extracellular and intracellular cholesterol accumulation called?

Answer 45

Atherosclerosis and Xanthomas (inside macrophages)

Question 46

What is exogenous accumulation of carbon dust?

Answer 46

Anthracosis

Question 47

What is endogenous accumulation of pigments?

Answer 47

Lipofuscin (wear and tear from aging)

Question 48

What is hemosiderin?

Answer 48

hemoglobin breakdown product; form of iron stored in cells

Question 49

What can cause metastatic calcification?

Answer 49

Hypercalcemia: increased serum calcium due to increased parathryroid hormone, destruction of bone, too much vitamin D