Cell Injury

Question 1

What occurs if a stressor is put on a cell in homeostasis? 2 outcomes.

Answer 1

Structural changes or functional changes

Question 2

What are 2 examples of cell stress? and what does stress on the cell result in

Answer 2

Cell vulnerability and dose intensity. Result in adaptation (metabolically or structurally) or injury (reversible and irreversible)

Question 3

4 mechanisms for cellular injuries

Answer 3

Decrease in ATP, Membrane damage, cytoskeleton damage, DNA damage

Question 4

Necrosis occurs due to which stressors?

Apoptosis occurs due to which stressors?

Answer 4

Necrosis: ATP depletion, membrane damage (mitochondria damage, lysosome burst, membrane disruption) and cytoskeleton damage.

Apoptosis: DNA damage. Accumulation of misfolded proteins.

Question 5

What are the changes that occur in a cell from injury to death?

Answer 5

Early ultrastructural changes that are reversible: Cytoplasm swelling and vacuoles appearing.

Microscopic changes that are irreversible: Pyknosis. Clumping of chromatin. First observable light microscope change.

Late microscope changes:
karyorhexis. Fragmenting of the nucleus.
Karyolysis. Nuclear material dissolves.

Cytoplasm swelling and vacuoles –> Pyknosis –> Karyorhexis–> karyolysis

Cytoplasm swelling and vacuoles –> Chromatin clumps -> Nucleus fragments –> Nuclear material dissolves.

Question 6

Most common cause of cell injury

Answer 6

Hypoxia. ATP is depleted, which causes pumps to stop working. Water and sodium will enter the cell, causing it to swell and vacuoles to appear.

Question 7

Hypoxia is ___

Anoxia is ___

Answer 7

Pinching of blood vessel

Blocked blood vessel

Question 8

Two types of hypoxic injuries

Answer 8

Ischemic (reduction of blood flow)

Anemic (RBC cannot deliver O2)

Question 9

Two types of reactive oxygen species

Answer 9

Radical (OH-, O2-) and non-radical forms (H202)

Question 10

ROS can cause which types of injuries?

Answer 10

Lipid per oxidation, protein degradation, and DNA damage. Significant over a period of time.

Question 11

Where are ROS generated?

Answer 11

Internally and externally. Mitochondria and certain immune cells.

Question 12

ROS sources

Answer 12

Mitochondria
Immune cells
Cigarette smoke 
Exercise 
Pollution 
Drugs, pesticides
Solvents
Reperfusion. (Tissue damage caused after period of ischemia)

Question 13

Two types of toxic injury

Answer 13

Direct- disrupt cellular function.

• Lead (CNS)
• Mercury (CNS)
• Carbon monoxide is anemic hypoxia.

Indirect- Toxic after metabolism.
-Ethanol. CNS and liver toxicity
-Ethambutol. Tb med. Toxic Optic neuropathy
Cyclosporine. Renal toxicity. Restasis.

Question 14

Two types of infectious injuries

Answer 14

Direct cellular damage: Bacteria byproduct (toxin) damages cell

Indirect cellular damage: Activated inappropriate immune response

Question 15

Genetic/metabolic injury. Two types

Answer 15

Acquired: Fatty liver disease, hepatolenticular degeneration (inability to handle copper) and type 2 diabetes

Congenital: Sickle cell anemia

Question 16

4 types of traumatic injuries

Answer 16

Blunt force, penetrating, sharp, ionizing radiation

Question 17

Atrophy

Answer 17

Decreased cell size. Can be due to injury or decreased use.

Question 18

Hypertrophy

Answer 18

Increased cell size. Getting swole or uterus during pregnancy. Left ventricular hypertrophy (chronic HBP)

Question 19

Hyperplasia

Answer 19

Increased cell number. Breast cells during pregnancy, calluses.

Question 20

Metaplasia

Answer 20

Change from one cell type to another. Extropion.

Question 21

Dysplasia.

Answer 21

Not an adaptation. Shows damage. Precursor to cancer.

Question 22

Primary theory of aging

Answer 22

Accumulation of injuries (Stress) and genetically controlled program (telomeres)

Mitochondria becomes less efficient

Question 23

Coagulative necrosis

• affects which tissues
• begins with what
• Causes what

Answer 23

Kidneys, heart, and adrenal glands.
Begins with ischemia.
Causes protein denaturation

Question 24

Liquefactive necrosis

• Affects which tissues?
• What enzymes are involved
• Might form what?

Answer 24

Affects neurons and glial cells of the brain
Hydrolytic enzymes involved
Might form abscess or cyst

Question 25

Caseous (cheese like)
Mainly from what kind of infection?
Combination of which two necrosis?

Answer 25

From Tb

Combo of coagulative and liquefactive

Question 26

Gangrenous necrosis (large area)
Dry?
Wet?
Gas?

Answer 26

Dry: Coagulative
Wet: Liquefactive
Gas: Infection with anaerobic bacteria

Question 27

Fat necrosis
Occurs in which tissues?
Action of what may cause saponification

Answer 27

Occurs in breast, pancreas, abdominal organs. With fatty tissues.
Lipases cause soap

Question 28

Necrosis 
Cause
Cells affected?
Cell morphology 
Cell membrane 
Outcome

Answer 28

Cause: Exogenous injury 
Cells affected: many 
Cell morphology: Swollen, ruptured
Cell membrane: Ruptured 
Outcome: Phagocytosis by neutrophils

Question 29

Apoptosis 
Cause
Cells affected?
Cell morphology 
Cell membrane 
Outcome

Answer 29

Cause: Exogenous or endogenous
Cells affected: Single 
Cell morphology: Rounded up, fragmented bodies
Cell membrane: Functionally intact
Outcome: Phagocytosis by macrophage

Question 30

Algor mortis

Answer 30

Cooling of body

Question 31

Livor mortis

Answer 31

Pooling of blood

Question 32

Rigor mortis

Answer 32

Contraction of muscles

Question 33

Postmorten autolysis (endogenous)

Answer 33

Enzyme break down tissue time.

Question 34

Putrefaction (exogenous)

Answer 34

Bacteria break down tissue time.