1.2 Cellular Changes

Question 1

• What is (cellular) STRESS?

- What does it lead to?

Answer 1

• Stress is a physical, emotional, or chemical factor
• Leads to changes/injuries that are initially reversible
• Leads to increased functional demand

Question 2

When do cellular changes become irreversible?

Answer 2

After prolonged stress

Question 3

What is NECROSIS?

Answer 3

• Death of cells in tissues or organs

- Result of severe/prolonged stress

Question 4

What are all the reversible CELL GROWTH CHANGES?

Answer 4

• ATROPHY - cell size decrease
• HYPERTROPHY - cell size increase
• HYPERPLASIA - cell number increase
• METAPLASIA - cell type change
• DYSPLASIA - cell structure change/mismatch

Question 5

Define ATROPHY

Answer 5

• DECREASE in cell SIZE

- caused by DISUSE of cell

Question 6

Define HYPERTROPHY

Answer 6

• INCREASE in cell SIZE
• may/not be beneficial
• Enlarged tissue mass

Question 7

Define HYPERPLASIA

Answer 7

• INCREASE in cell NUMBER

- Enlarged tissue mass

Question 8

Define METAPLASIA

Answer 8

• CHANGE in cell TYPE

Question 9

Define DYSPLASIA

Answer 9

• CHANGE in cell STRUCTURE
• cells become IMMATURE
• all cells NON UNIFORM

Question 10

What are the irreversible CELL GROWTH CHANGES

Answer 10

• NEOPLASIA - cancer

- ANAPLASIA - undifferentiated cells

Question 11

Define NEOPLASIA

Answer 11

• new growth/tumor

Question 12

Define ANAPLASIA

Answer 12

• extremely undifferentiated cells

- implies advanced cancer

Question 13

What are other REVERSIBLE cell injuries?

Answer 13

• Cellular swelling

- Intracellular Accumulations

Question 14

What are the Etiologies (causes) of CELL INJURY?

Answer 14

• Hypoxia
• Ischemia
• Free radical
• Nutritional
• Infectious
• Chemical
• Physical
• Mechanical

Question 15

Define HYPOXIA

Answer 15

Injury due to Lack of oxygen

Question 16

Define ISCHEMIA

Answer 16

Lack of blood flow

• leads to buildup of metabolic waste
• & lack of nutrition

Question 17

Define FREE RADICAL INJUY

Answer 17

Injury due to Poor/lack of metabolism of certain substances

or, due to large amount of energy exposure

Question 18

Define INFECTIOUS INJURY

Answer 18

An additional injury due to the triggering of an immune response & the attacking of bacteria

Question 19

Define CHEMICAL INJURY

Answer 19

• Can be directly from chemicals

- Or indirectly from substances that metabolize into chemicals that react negatively with the body

Question 20

Give examples of situations that give rise to PHYSICAL INJURIES

Answer 20

• changes in altitude
• changes in atmospheric pressure
• extreme temperature changes

Question 21

Define MECHANICAL INJURY

Answer 21

Injury resulting from trauma

- can be ELECTRIC - which disrupts neural & cardiac impulses & leads to thermal burns

Question 22

What is HYDROPIC SWELLING

Answer 22

• CELLULAR SWELLING
• usually the FIRST manifestation of REVERSIBLE cell injury
• due to WATER accumulation from malfunction of SODIUM POTASSIUM PUMP
• –megaly

Question 23

What are INTRACELLULAR ACCUMULATIONS

Answer 23

• when normal body substances (protein, melanin) build up in body
• or, build up due to faulty metabolism
• or, exogenous (foreign) product that is unable to be processed/metabolized

Question 24

What is one type of reversible intracellular accumulation?

Answer 24

• LIPID DEPOSITION

- or Lipid accumulation

Question 25

Define FREE RADICAL FORMATION

Answer 25

- FREE RADICAL = uncharged atom/atoms that contain unpaired electron = negative charge - Unstable, damaging to cell - Occurs due to exposure to large amounts of energy - Cause damage via lipid peroxidation

Question 26

Define LIPID PEROXIDATION

Answer 26

- when free radicals steal electrons from lipid membranes & damage the cell - the lipid then degrades

Question 27

Define NECROSIS

Answer 27

- Cell death in organ/tissue - Can result in addtl. damage (starts locally, spreads) - Usually results from ischemia/injury - Cell ruptures (membrane damage) & contents spill out - Triggers inflammatory process

Question 28

What are the 4 types of NECROSIS

Answer 28

- coagulative - liquefactive - fat - caseous

Question 29

Define COAGULATIVE NECROSIS

Answer 29

- Cell death due to ISCHEMIA/lack of blood flow then - energy is lost - sodium-potassium pump stops working - sodium → water builds up in cell - cell swells - attempts to produce ATP (b/c energy lost) results in acid build up - acid + water ruptures membrane

Question 30

Define LIQUEFACTIVE NECROSIS

Answer 30

- Dead cell/tissue becomes liquid - Dead cells are dissolved by lysosomal enzymes - surrounding healthy tissue is damaged - abscess/cyst forms = with liquid inside

Question 31

Define CASEOUS NECROSIS

Answer 31

- Death to lung cells | - Result of TUBERCULOSIS

Question 32

Define FAT NECROSIS

Answer 32

- Adipose/fat tissue death due to TRAUMA

Question 33

What are some consequences of NECROSIS

Answer 33

- loss of function - localized inflammatory response - or, systemic response e.g. fever - bacterial invasion site → infection

Question 34

Define GANGRENE

Answer 34

- cell death of LARGE area of tissue | - due to lack of blood supply to body part

Question 35

What are the types of GANGRENE?

Answer 35

- dry - wet - gas

Question 36

Define DRY GANGRENE

Answer 36

- form of COAGULATIVE necrosis (cell death-lack of blood from poor circulation) - slow spreading - black, dry, wrinkled tissue - strict line of demarcation - tissue must be removed

Question 37

Define WET GANGRENE

Answer 37

- form of LIQUEFACTIVE necrosis - fast spreading - found more often in internal organs - no strict line of demarcation

Question 38

Define GAS GANGRENE

Answer 38

- comes after dry/wet gangrene - from infection of dead/necrotic tissue by Clostridium (anaerobic bacteria) - forms gas bubbles (as bacteria is metabolized)

Question 39

Define Necrotic Tissue

Answer 39

DEAD TISSUE

Question 40

Define APOPTOSIS

Answer 40

- triggering of cascade that activates cell suicide - no inflammation, no further damage - "clean, neat, cell suicide" - allows new healthy cell formation