WEEK ONE - IRREVERSIBLE CHANGES + NECROSIS (TAE)

Question 1

Irreversible changes: the basics

Answer 1

Most diseases begin with cell injury. When “the point of no return” is reach and cell death is inevitable depends on many factors.
- Two types of these irreversible changes.

Question 2

Reversible changes:#1

Answer 2

Hydropic swelling. If the body gets oxygen again, therefore activating the na/k pump then we can shrink the cell back to normal functioning size.

Question 3

Reversible changes: #2

Answer 3

Intracellular accumulation. Can be many substances that build up in the cell. If we can get those substances out, then we can go back to functioning. Often happens in the Liver, Kidneys, and Lungs.
- EX: alcohol (fatty liver). Glycogen (in diabetic kidney), or tar (in a smoker’s lungs).

Question 4

Reversible changes: #3

Answer 4

Atrophy. Size decreases and so does function. Causes of atrophy: Ischemia, decreased endocrine stim, denervation, malnutrition, decreased use, cell injury, aging. U can see how some of these can be remedied, thus restoring the cell.

Question 5

Reversible changes: #4

Answer 5

Hypertrophy. Increased organ/cell function. Need of cell increases, and u need more protein. Sometimes this is a good thing, but we don’t want some organs to always be hypertrophic. EX: Left ventricular hypertrophy in pt with high B/P.

Question 6

Reversible changes: #5

Answer 6

Hyperplasia. More of the same type of cell. Hormone increases to cause good or bad changes.

Question 7

Reversible changes: #6

Answer 7

Metaplasia. Changing one type of adult cell to a different type. Can be good or bad. Example: a callous that grows in a spot of chronic irritation.

Question 8

Reversible changes: #7

Answer 8

Dysplasia. Sus but we’ll allow it. Typically a disorganized change gone wrong. precancerous. Abnormal development.

Question 9

Adult dysplasia…common types

Answer 9

Cervical (low vs high grade). HPV is linked to cervical cancer in some way. Higher risk if immunocompromised and/or a smoker.

Question 10

IRREVERSIBLE (1/2): Apoptosis

Answer 10

Natural cell suicide. Neighboring cells ingest the cell. Quick and clean, and not associated with inflammation. Triggered by the cell itself or diseases like cancer or organ impairment

Question 11

IRREVERSIBLE (2/2): Cell necrosis

Answer 11

Cell death. Always pathologic. due to ischemia or toxic injury. Leads to cell rupture & inflammation.

Question 12

Major types of necrosis (4)

Answer 12

1. Coagulative
2. Liquefactive
3. Fat
4. Caseous

Question 13

Coagulative necrosis

Answer 13

• Commonly from hypoxia. Most common type. proteins in body coagulate (like egg whites).
• Mostly in extremities, kidneys, adrenal glands, heart.
• Appears dry & black

Question 14

Liquefactive necrosis

Answer 14

• Commonly results from ischemia to neurons
• Enzymes of these cells digest themselves.
• Lysozomes rupture to kill The bacteria and cell dies and is liquefied
• Pus is formed

Question 15

Fat necrosis

Answer 15

• death of adipose
• Usually from trauma or pancreatitis
• Enzymes destroy fat
• Appears white and chalky

Question 16

Caseous necrosis

Answer 16

• Occurs with TB
• Like cottage cheese
• Dead cells are walled off by WBCs creating a “tubercle” seen on XRAY
• Never totally gone

Question 17

Gangrene

Answer 17

Cellular death to a large area of tissue

Question 18

Dry gangrene

Answer 18

• A type of coagulative necrosis that appears dry, black, and wrinkled. Often on extremities.

Question 19

Wet gangrene

Answer 19

type of liquifactive necrosis that appears cold, wet, swollen. Smells awful. Occurs in internal organs or external organs. Very life threatening.

Question 20

Gas gangrene

Answer 20

Formation of gas bubble sin damaged muscle tissue.
- caused by anaerobic bacteria (clostridium spp.)
- Releases toxins + often fatal
- Hard to treat

Question 21

Avascular Necrosis (AVN): Necrosis after femoral neck fracture

Answer 21

• Can be a major complication as a result of a bone injury that causes a lack of blood supply to an area of bone. Leads to bone cell ischemia and subsequent cell death
• can occur after internal fixation of a femoral neck fracture.