PATH 3610 FINAL | 328 QUESTIONS AND ANSWERS |
WITH COMPLETE SOLUTION.
What are some possible causes of degeneration and necrosis? Answer -
Depletion of ATP, Impaired cell membrane function, Intracellular accumulation,
Genetic Abnormalities
What is hypoxia/ischemia? Answer - Insufficient oxygen in the cells & reduced
blood supply
What would cause a depletion of ATP? Answer - Hypoxia/ischemia,
hypoglycemia, enzyme inhibition, uncoupling of oxidative phosphorylation
What is hypoglycemia? Answer - Low blood glucose
What are the effects of defective energy production? Answer - Intracellular
Accumulation of Water: water/sodium channels not working properly, w/o that
balance water starts to fill the cell
Swelling of Cytoplasmic Organelles: the above causes organelles, like the
mitochondria, to swell, causing the uncoupling of oxidative phosphorylation
Switch to Anaerobic Glycolysis: leads to increase of lactic acid, pH decreases,
further disruption of organelle membranes
What causes impaired membrane function? Answer - Free radicals (damaging
the membrane), Activation of complement system, & Direct Lysis of the
membrane (direct insertion, lysis by immune response)
,What are the effects of impaired membrane function? Answer - Loss of
Structural Integrity: if bad enough, cell will rupture and die
Loss of Function: swelling -> loss of function
Deposition of Lipofuscin: damaged bits of cell membrane is deposited in the
cytoplasm result from free radical peroxidation, considered normal in aging
What could cause triglyceride accumulation in the liver? Answer - Increased
mobilization of adipose tissue, so increased amounts of fatty acids reach the
liver. Overactivity of certain enzyme systems increase the conversion of fatty
acids into triglycerides. The oxidation of triglycerides to other forms is
decreased. Apoprotein synthesis is decreased.
How does iron accumulate in the body? Answer - Hemoglobin (Hb) is broken
down at sites of hemorrhage (local hemosiderosis). Usually deposited in
macrophages or connective tissue as hemosiderin. Not generally harmful,
unless too extreme
How is bilirubin formed and excreted? Answer - -Old/damaged RBCs broken
down & recycled by macrophages
-Porphyrin ring (from Hb) is catabolized to bilirubin
-Bilirubin binds to albumin (unconjugated/lipid soluble) and travels to the liver
-In the liver, it's conjugated to glucuronide (now water soluble) and excreted by
liver cells into the bile duct
-Removed via the feces w/ the bile
How does jaundice come about? Answer - Jaundice is the accumulation of
bilirubin
,-Hemolysis (destruction of RBCs): if RBC break down increases too much, the
production of bilirubin also increases, liver cannot conjugate it fast enough,
Unconjugated serum bilirubin increases
-Hepatocellular dysfunction: if liver is injured, uptake, conjugation and
excretion of bilirubin will be affected, conjugated and unconjugated levels will
both increase
-Obstruction to bile flow (cholestasis): an obstruction to the bile duct will affect
excretion, Conjugated bilirubin will reflux into the plasma, causing jaundice
What are the three types of morphological evidence of necrosis? Answer - -
Gross Evidence: microscopic changes that can be seen by the unaided eye
-Cytoplasmic Evidence: cytoplasm becomes deeply stained and more
homogenous, may have a bubbly or vacuolated appearance, abnormal deposits
of calcium
-Nuclear Evidence: nuclear chromatin clumps, and the nucleus becomes
smaller and more densely staining
What is coagulation necrosis? Answer - Cell death due to ischemia
What is liquefaction necrosis? Answer - Dead cells liquefy (pus) because of
release of cell enzymes from inflammatory cells
What is gangrenous necrosis/ gangrene? Answer - Condition of a limb (usually
a leg) that has lost its blood supply & has undergone coagulation necrosis
involving multiple tissue layers
What is caseous necrosis? Answer - A form of coagulative necrosis in which a
thick, yellowish, cheesy substance forms
, What is fat necrosis? Answer - A specialized form of liquefaction necrosis
caused by the action of lipolytic enzymes
What are some clinical problems associated with tissue necrosis? Answer - -
Altered function: can result if sufficient numbers of cells become necrotic
-Loss of Tissue: severe cell and tissue death can result in loss of the affected
tissue or organ
-Secondary Infection: necrotic tissue often contains little-to-no inflammation;
necrotic tissue can become an ideal growth medium for infection (usually if
moist), as they are beyond the reach of inflammatory cells and the immune
system
-Systemic Effects: fever and increased white blood cell counts
-Local Effects: depends on what tissue is affected and extent of necrosis
-Release of Enzymes from a Necrotic Cell
What are some differences between apoptosis and necrosis? Answer - -
Necrosis is passive and disorderly, Apoptosis is active, organized and orderly,
requires energy and follow a "plan"
-Necrosis is fragmented and intracellular proteins leak out, while Apoptosis
keeps its cellular outlines intact
-Necrosis produces cell debris and releases inflammatory mediators, while
Apoptosis produces neatly packaged cell fragments
Describe the mitochondrial pathway of apoptosis. Answer - -BH3-only proteins
(part of the Bcl-2 family which controls mitochondria permeability), sense a
lack of survival signals or DNA or protein damage
-These BH3-only proteins activate effector molecules that increase
mitochondrial permeability
-The mitochondria become leaky and various substances, such as cytochrome
c, enter the cytosol and activate caspases
WITH COMPLETE SOLUTION.
What are some possible causes of degeneration and necrosis? Answer -
Depletion of ATP, Impaired cell membrane function, Intracellular accumulation,
Genetic Abnormalities
What is hypoxia/ischemia? Answer - Insufficient oxygen in the cells & reduced
blood supply
What would cause a depletion of ATP? Answer - Hypoxia/ischemia,
hypoglycemia, enzyme inhibition, uncoupling of oxidative phosphorylation
What is hypoglycemia? Answer - Low blood glucose
What are the effects of defective energy production? Answer - Intracellular
Accumulation of Water: water/sodium channels not working properly, w/o that
balance water starts to fill the cell
Swelling of Cytoplasmic Organelles: the above causes organelles, like the
mitochondria, to swell, causing the uncoupling of oxidative phosphorylation
Switch to Anaerobic Glycolysis: leads to increase of lactic acid, pH decreases,
further disruption of organelle membranes
What causes impaired membrane function? Answer - Free radicals (damaging
the membrane), Activation of complement system, & Direct Lysis of the
membrane (direct insertion, lysis by immune response)
,What are the effects of impaired membrane function? Answer - Loss of
Structural Integrity: if bad enough, cell will rupture and die
Loss of Function: swelling -> loss of function
Deposition of Lipofuscin: damaged bits of cell membrane is deposited in the
cytoplasm result from free radical peroxidation, considered normal in aging
What could cause triglyceride accumulation in the liver? Answer - Increased
mobilization of adipose tissue, so increased amounts of fatty acids reach the
liver. Overactivity of certain enzyme systems increase the conversion of fatty
acids into triglycerides. The oxidation of triglycerides to other forms is
decreased. Apoprotein synthesis is decreased.
How does iron accumulate in the body? Answer - Hemoglobin (Hb) is broken
down at sites of hemorrhage (local hemosiderosis). Usually deposited in
macrophages or connective tissue as hemosiderin. Not generally harmful,
unless too extreme
How is bilirubin formed and excreted? Answer - -Old/damaged RBCs broken
down & recycled by macrophages
-Porphyrin ring (from Hb) is catabolized to bilirubin
-Bilirubin binds to albumin (unconjugated/lipid soluble) and travels to the liver
-In the liver, it's conjugated to glucuronide (now water soluble) and excreted by
liver cells into the bile duct
-Removed via the feces w/ the bile
How does jaundice come about? Answer - Jaundice is the accumulation of
bilirubin
,-Hemolysis (destruction of RBCs): if RBC break down increases too much, the
production of bilirubin also increases, liver cannot conjugate it fast enough,
Unconjugated serum bilirubin increases
-Hepatocellular dysfunction: if liver is injured, uptake, conjugation and
excretion of bilirubin will be affected, conjugated and unconjugated levels will
both increase
-Obstruction to bile flow (cholestasis): an obstruction to the bile duct will affect
excretion, Conjugated bilirubin will reflux into the plasma, causing jaundice
What are the three types of morphological evidence of necrosis? Answer - -
Gross Evidence: microscopic changes that can be seen by the unaided eye
-Cytoplasmic Evidence: cytoplasm becomes deeply stained and more
homogenous, may have a bubbly or vacuolated appearance, abnormal deposits
of calcium
-Nuclear Evidence: nuclear chromatin clumps, and the nucleus becomes
smaller and more densely staining
What is coagulation necrosis? Answer - Cell death due to ischemia
What is liquefaction necrosis? Answer - Dead cells liquefy (pus) because of
release of cell enzymes from inflammatory cells
What is gangrenous necrosis/ gangrene? Answer - Condition of a limb (usually
a leg) that has lost its blood supply & has undergone coagulation necrosis
involving multiple tissue layers
What is caseous necrosis? Answer - A form of coagulative necrosis in which a
thick, yellowish, cheesy substance forms
, What is fat necrosis? Answer - A specialized form of liquefaction necrosis
caused by the action of lipolytic enzymes
What are some clinical problems associated with tissue necrosis? Answer - -
Altered function: can result if sufficient numbers of cells become necrotic
-Loss of Tissue: severe cell and tissue death can result in loss of the affected
tissue or organ
-Secondary Infection: necrotic tissue often contains little-to-no inflammation;
necrotic tissue can become an ideal growth medium for infection (usually if
moist), as they are beyond the reach of inflammatory cells and the immune
system
-Systemic Effects: fever and increased white blood cell counts
-Local Effects: depends on what tissue is affected and extent of necrosis
-Release of Enzymes from a Necrotic Cell
What are some differences between apoptosis and necrosis? Answer - -
Necrosis is passive and disorderly, Apoptosis is active, organized and orderly,
requires energy and follow a "plan"
-Necrosis is fragmented and intracellular proteins leak out, while Apoptosis
keeps its cellular outlines intact
-Necrosis produces cell debris and releases inflammatory mediators, while
Apoptosis produces neatly packaged cell fragments
Describe the mitochondrial pathway of apoptosis. Answer - -BH3-only proteins
(part of the Bcl-2 family which controls mitochondria permeability), sense a
lack of survival signals or DNA or protein damage
-These BH3-only proteins activate effector molecules that increase
mitochondrial permeability
-The mitochondria become leaky and various substances, such as cytochrome
c, enter the cytosol and activate caspases
