1 - Cell Injury and Death

Question 1

Hypoxemia: what results in decreased PaO2?

Answer 1

High altitude

Question 2

Hypoxemia: what results in increased PaCO2 which results in decreased PaO2?

Answer 2

Hypoventilation

Question 3

Decreased O2 Carrying Capacity: PaO2 and SaO2 are normal

Answer 3

Anemia

Question 4

Decreased O2 Carrying Capacity: what is the result of CO Poisoning - CO binds Hb better than O2?

Answer 4

PaO2 normal

SaO2 decreased

Question 5

Decreased O2 Carrying Capacity: What is the result of Methemoglobinemia - iron in heme is oxidized to Fe3+ which can’t bind O2?

Answer 5

PaO2 normal

SaO2 decreased

Question 6

Mechanisms of Decreased ATP: leads to Na+/K+ pump dysfunction, which leads to what?

Answer 6

increased Na and water in cytosol

Question 7

Mechanisms of Decreased ATP: leads to Ca2+ pump dysfunction, which leads to what?

Answer 7

increased Ca2+ in cytosol

Question 8

Mechanisms of Decreased ATP: leads to switch to anaerobic glycolysis, which results in what?

Answer 8

Lactic acid buildup and Low pH, which denatures protein and precipitates DNA

Question 9

Protection from ROS: Free radicals and ROS decay spontaneously and are broken down by what?

Answer 9

Superoxide Dismutase (O2- to H2O2)
Glutathione Peroxidases and Catalase (H2O2 to H2O)

Question 10

Protection from ROS: what is the role of Antioxidants (Vitamins A, C, E, and B-carotene)?

Answer 10

block free radical formation or scavenge them

Question 11

Mechanisms - Ca2+ Influx: what cases release of intracellular Ca2+ stores –> cytosol –> influx across pm?

Answer 11

Ischemia

Question 12

Mechanisms - Ca2+ Influx: Elevated cytosolic Ca2+ activates enzymes which …

Answer 12

damage membranes, proteins, DNA and ATP

Question 13

Mechanisms - Ca2+ Influx: Elevated cytosolic Ca2+ can also induce apoptosis, but what 2 ways?

Answer 13

• Activation of caspases

- Increasing mitochondrial permeability (cyto c release)

Question 14

Mechanisms - Membrane Damage: What does Plasma Membrane Damage lead to? (2)

Answer 14

• Cytosolic enzymes leaking into serum

- Ca Influx

Question 15

Mechanisms - Membrane Damage: What does Mitochondrial Membrane Damage lead to? (2)

Answer 15

• Loss of ETC

- Cytochrome c leaking into cytosol (activates apoptosis)

Question 16

Mechanisms - Membrane Damage: What does Lysosome Membrane Damage lead to?

Answer 16

Hydrolytic enzymes leaking into the cytosol, which are activated by high intracellular Ca2+ (–> enzymatic digestion of cellular components)

Question 17

Cell Death: loss of nucleus through nuclear condensation (DNA condenses into shrunken basophilic mass)

Answer 17

pyknosis

Question 18

Cell Death: loss of nucleus through fragmentation (pyknotic nuclei membrane ruptures and nucleases undergoes fragmentation)

Answer 18

karyorrhexis

Question 19

Cell Death: loss of nucleus through dissolution (chromatin dissolution due to action of DNAases and RNAases)

Answer 19

karyolysis

Question 20

In what type of Necrosis is the cell shape and organ structure preserved due to … of proteins but the nucleus disappears?

Answer 20

Coagulative Necrosis

Question 21

Coagulative Necrosis is seen with … of any organ except the brain.

Answer 21

ischemic infarction

Question 22

Liquefactive Necrosis is characteristic of …, where proteolytic enzymes from microglial cells liquefy the …

Answer 22

Brain infarction

Question 23

Liquefactive Necrosis is characteristic of …, where proteolytic enzymes from neutrophils liquefy tissue

Answer 23

Abscess

Question 24

Coagulative Necrosis that resembles mummified tissue is called?

Answer 24

Dry Gangrene

Question 25

Gangrenous Necrosis is characteristic of ischemia of what two things?

Answer 25

lower limb and GI tract

Question 26

Gangrenous Necrosis: if superimposed infection of dead tissues occurs, then liquefactive necrosis ensues, this is called

Answer 26

Wet Gangrene

Question 27

Caseous Necrosis is seen as soft and friable with “cheese-like” appearance, where is this characteristic pattern seen?

Answer 27

Tuberculosis or Deep Fungal Infections

Question 28

In Caseous Necrosis tissue architecture is replaced by defined foci of inflammation called …

Answer 28

granulomas

Question 29

Fibrinoid Necrosis is the necrosis of a vessel wall leading to leakage of what into the wall, which stains bright pink

Answer 29

fibrin and other proteins

Question 30

What is Fibrinoid Necrosis caused by?

Answer 30

Immune Reactions and Malignant Hypertension

Question 31

Apoptosis Sequence: initiated by … which activate … and …

Answer 31

caspases; endonucleases and proteases (degrade cytoskeleton)

Question 32

Apoptosis Sequence: as the dying cell shrinks, the cytoplasm becomes more …, and the nucleus condenses and fragments.

Answer 32

eosinophilic

Question 33

Apoptosis Intrinsic (mito) Pathway: Cell Injury, DNA damage or lack of growth signals, cause a decrease in what, which allows city c to leak from mito into cytoplasm –> activates caspases –> apoptosis?

Answer 33

BCL-2 protein family (anti-apoptic)

Question 34

Apoptosis Extrinsic Pathway: Cells express …; … ligand on activated T cells binds to … and activates caspases leading to apoptosis

Answer 34

Death receptors; Fas

Question 35

Apoptosis Cytotoxic T Cell Mediated: CD8+ bind infected host cells or tumor cells and releases what into the target cell –> caspases activation –> apoptosis

Answer 35

Granzymes - granule proteases

Question 36

Pigments: “wear and tear” brownish-yellow complex of lipid and protein derived from previous free radical damage of membranes. Accumulates with age or atrophy in heart, liver and brain (a lot of it causes “brown atrophy”)

Answer 36

Lipofuscin

Question 37

Abnormal tissue deposition of calcium salts, if occurs in dead or dying tissues they are called, … (there is normal serum calcium)

Answer 37

Dystrophic Calcifications

Question 38

Abnormal tissue deposition of calcium salts, if occurs in normal tissues they are called, … and are almost always caused by hypercalcemia.

Answer 38

Metastatic Calcifications