Cell Injury

Question 1

What is the main reason of cell death

Answer 1

Oxygen deprivation
Hypoxia
Ischemia

Question 2

What is Hypoxia

Answer 2

Loss of blood supply from impeded blood flow or reduced venous drainage in a tissue

Question 3

What is Ischemia

Answer 3

Compromises the availability of metabolic substrates including glucose, tends to injure tissues faster than hypoxia

Question 4

Other causes of Cell injury

Answer 4

Physical agents: mechanical trauma, burns,cold
Chemical agents and drugs: glucose, salt, hypertonic concentration, poisons, environmental pollutants
Infectious agents
Immunologic reactions: endogenous self ag, autoimmune disease,reaction to foreign protein or drug.
Genetic rearrangements: genetic injury, chromosomal abnormality
Nutritional imbalance: anorexia nervosa, obesity, atherosclerosis.

Question 5

The cellular response to injurious stimuli depends on

Answer 5

Type of injury
Duration
Severity

Question 6

The consequences of cell injury depend on the

Answer 6

Type
State
Adaptability of the injured cell

Question 7

Which essential cellular components with an abnormality results with cell injury

Answer 7

Aerobic respiration involving mito oxidative phosphorilation and production of ATP
Maintenance of the integrity of cell membranes
Protein synthesis
Preservation of the integrity of the genetic apparatus of the cell

Question 8

Which structure is responsible for turning injury reversible to irreversible

Answer 8

Integrity of cell membranes

Question 9

Effects of degradation in ATP to Na pump

Answer 9

Na pump activity decreases— Ca+, H20 and Na+ influx and K+ efflux increases— ER swelling, Cellular swelling, Loss of microvilli, BLEBS

Question 10

Effects of ATP decrease to Anaerobic glycolysis

Answer 10

Anaerobic glycolysis increases— glycogen and pH decreases — clumping of nuclear chromatin

Question 11

Most common types of cellular injury

Answer 11

Ischemic
Hypoxic

Question 12

Reperfusion injury

Answer 12

When blood flow is restored to cells that have been previously ischemic, injury can be excerbated.

Question 13

What is the first effect of Hypoxia

Answer 13

Loss of oxidative phosphorylation and ATP generation by mitochondria

Question 14

When the changes in the cell caused by Hypoxia can reverse

Answer 14

When oxygenation is restored

Question 15

What happens when ATP depletion continuous

Answer 15

Membrane dysfunction
Mitochondrial membrane damage

Question 16

What causes the release of cytochrome c

Answer 16

ATP depletion

Question 17

What is the result effect of loss of the membrane integrity

Answer 17

Massive influx of Ca
Which will inhibit the cellular enzymes denaturation of proteins and cytologies alterations characteristic of coagulation necrosis.

Question 18

Effects of Free Radicals to cell to cause injury

Answer 18

Lipid peroxidation of membranes
Oxidative modification of proteins
Damage to DNA

Question 19

Which series of enzymes act as a free radical scavenging systems

Answer 19

Catalase
Superoxide dismutase
Glutathione peroxidase

Question 20

How does chemicals cause cellular injury

Answer 20

1- Directly by binding to critical molecular component
2- Indirectly by conversion to reactive toxic metabolites
Sometimes: CCL4, Acetaminophen

Question 21

Which mechanisms remove free radicals and minimize cellular injury

Answer 21

Antioxidants
Binding of the ions to storage and transport proteins

Question 22

What are the marks of the irreversible injury

Answer 22

Mitochondrial vacuolization
Extensive damage to cell membranes
Swelling of lysosomes
the appearance of large amorphous densities in mitochondria

Question 23

Injury of lysosomal membranes result with

Answer 23

Leakage of enzymes into the cytoplasm and by their activation to enzymatic digestion of cell and nuclear components

Question 24

What are the processes that cause the basic morphological changes of necrosis

Answer 24

Denaturation of proteins
Enzymatic digestion of organelles and other Cytosolic components

Question 25

Pyknosis

Answer 25

Small dense nuclei

Question 26

Karyolysis

Answer 26

Faint dissolved nucleus

Question 27

Karyrrhexis

Answer 27

Nucleus broken up into many clumps

Question 28

Dystrophin Cacification

Answer 28

Necrotic cells may attack calcium salts in the form of glandular basophilic deposits

Question 29

What are the types of necrosis

Answer 29

Coagulation necrosis
Liquefaction necrosis
Caseous necrosis
Fat necrosis
Fibrinoid necrosis

Question 30

What is Coagulation necrosis

Answer 30

Most common type
Characterized by denaturation of cytoplasmic proteins with preservation of the framework of the coagulated cell
Occurs in myocardium, kidney, liver…

Question 31

What is Liquefaction necrosis

Answer 31

Occurs when autolysis and heterolysis prevail over protein denaturation
Necrotic area is soft and filled with fluid
Mostly seen in localized bacterial infections and in brain(?)

Question 32

Caseous necrosis

Answer 32

Characteristics of TUBERCULOSIS lesions
Appears grossly as soft friable material
Microscopically as amorphous eosinophilia material with cell debris

Question 33

Fat necrosis

Answer 33

Necrosis in adipose tissue
Induced by the activation of lipases then complex with Ca to create Ca soaps

Question 34

What is Fibrinoid Necrosis

Answer 34

Special form of necrosis seen in immune reactions involving BV
Occurs when compexes of ag and ab are deposited in the walls of arteries
Fibrin leakage