1: Celluar Changes - Damage

Question 1

Apoptosis

Answer 1

programmed cell death

Question 2

Ischemia

Answer 2

deficit of oxygen supply to cells

• due to reduced blood flow
• dec O2 levels

Question 3

What can ischemia lead to?

Answer 3

Hypoxia

Question 4

Hypoxia

Answer 4

reduced oxygen in tissues

- reduced O2 available

Question 5

Physical damage in result from?

Answer 5

Excessive heat or cold
- frost bite, burn

Radical exposure
- free radicals: damages DNA

Question 6

Mechanical damage can result from?

Answer 6

Excess pressure and tearing

ie: injuries/cuts

Question 7

Chemical toxins can be?

Answer 7

Exogenous

Endogenous

Question 8

Exogenous

Answer 8

from environment (external)

Question 9

Endogenous

Answer 9

from inside of body (internal)

- ie: unwannted by products -> free radicals (cause chain rxn of cell damage)

Question 10

Other causes of damage

Answer 10

• microorganisms: bacteria + viruses + protozoa+ fungi
• abnormal metabolites: altered metabolism, genetic disorders, inborn errors of metabolism
• nutritional deficits: vitamin deficiencies
• imbalances of fluid or electrolytes

Question 11

Describe the process of cellular damage

Answer 11

1. cells wells with waters/lipids
   - lose control of storage and transport capability
   - store increased amts of lipids/water
2. altered metabolic reactions -> loss of function
   * if injury/cause removed quickly -> cell recover/repair
3. irreversibly changes -> apoptosis or necrosis
4. morphological changes in nucleus + w/i cell
   - cell swelling -> rupture
   - nucleus disintegration -> cell death
5. lysis

Question 12

Lysis

Answer 12

dissolution of cell by lysosomal enzymes into tisse

• cell bursting
• causes inflammation and damage to nearby cells (necrosis)

Question 13

Necrosis

Answer 13

when group of cells dies

- disintegration of cell nucleus

Question 14

What are the 5 types of necrosis

Answer 14

1. Liquefaction
2. Coagulative: infarction
3. Fat
4. Caseous
5. Gangrene

Question 15

What are the the 5 types of necrosis based on?

Answer 15

based on outcome of cell death

Question 16

Liquefaction Necrosis

Answer 16

dead cells LIQUIFY due to released cell enzymes

- creamy yellow fluid

Question 17

Coagulative Necrosis

Answer 17

cell proteins are altered or denatures
- cells cannot function -> lose distinct shape/design
- maintain organization of tissue BUT are not receiving blood supply
maintain cell architecture post death
- ischemia or infarction may be cause of death

Question 18

Infarction

Answer 18

area of dead cells as a result of O2 deprivation

tissue death from failure of blood supply

Question 19

Fat Necrosis

Answer 19

fatty tissue (adipocytes) is broken down into fatty acids

• may cause inflammation
  ie: trauma to surrounding area -> releases lipases (fat splitting enzymes)
• only relevant to fat tissue

Question 20

Caseous (Caseation) Necrosis

Answer 20

Form of coagulative & liquefactive necrosis

• thick, yellowish “cheesy” substance forms
• unique to TB

Question 21

Gangrene Necrosis

Answer 21

area of necrotic tissue invaded by bacteria (infection)

• infection common after infarction in intestines or limb (due to interfered blood supply)
• must be removed surgically to prevent spread of infection

Question 22

What are the 3 types of gangrene necrosis

Answer 22

1. Dry
2. Wet
3. Gaseous

Question 23

Dry gangrene (mummification)

Answer 23

arterial (to tissue) blood supply involved

- coagulative necrosis: due to anoxic injury then infected

Question 24

Wet gangrene

Answer 24

fluid/pus producing
due to impaired venous supply return (venus drainage)
- from tissue back to heart, blood pools in limited space -> compression on surrounding nerves
- excess blood pooled = feeding ground for infec
- solution usually amputation as in extremities/organs
- usually seen with diabetics and develops rapidly

Question 25

Gas gangrene

Answer 25

due to gas producing bacteria (clostridia)

• enters dead tissue -> prod. toxin & gas bubbles inside affect area
  tx: antimicrobial & antitoxin