Cell Injury, Adaption, Death

Question 1

What are the two means of stimulation for cellular adaption?

Answer 1

Physiologic Stress - normal part of physiology

Pathologic Stress - abnormal

Question 2

What are responses to nonlethal stimuli either by physiologic or injurous?

Answer 2

• Hyperplasia
• Hypertrophy
• Atrophy
• Metaplasia

Question 3

What are the results of cell injury via ischemia, chemical injury, or infection?

Answer 3

Cell Injury:

• Acute Reversible
• Irreversible with necrosis and apoptosis

Question 4

What are the differences between Labile, Stable, and Permanent cells?

Answer 4

Labile cells = continuously growing, surface epithelial
- bladder, skin, GI, bronchials, etc
Stable Cells = Quiescent, minimal division, but have the ability to if need be in response to injury.
- Liver, kidney, pancreas, endothelial cells
Permanent Cells = Do not divide, nonproliferative
- Neurons and Cardiac

Question 5

Example of both types of hypertrophy?

Answer 5

• Physiologic: athletic muscles

- Pathologic: cardiac hypertrophy leading to HTN

Question 6

What are both types of Hyperplasia and examples?

Answer 6

Physiologic: Hormonal - puberty
Pathologic: Endometrial hyperplasia, excessive stimulation by growth factors
Increased risk of cancer

Question 7

What are examples of both types of Atrophy?

Answer 7

Reduction in size of cells, not related to death.
Physiologic: loss of hormonal stimulation
Pathologic: Broken arm/CVA, atrophy

Question 8

What is metaplasia?

Answer 8

The change of one cell type to another in various locations based upon stimulation.

Question 9

When does metaplasia occur and common locations?

Answer 9

Typically epithelial metaplasia, columnar to squamous or squamous to gastric epithelium, etc.
Bronchi of smokers (change from columnar)
Distal Esophagus in GERD to gastric cells

Question 10

What are male and female versions of hyperplasia?

Answer 10

• Endometrial Hyperplasia
• Benign Prostatic Hyperplasia
• HPV skin warts/lesions

Question 11

What is the common appearance of the tissue with hyperplasia?

Answer 11

Increased number of glands and nodes within the tissue due to the increased number of cells

Question 12

What is the only organ that can undergo hyperplasia and hypertrophy?

Answer 12

Uterus, during pregnancy.

Question 13

What is the biggest concern regarding metaplasia?

Answer 13

Increased risk of cancer of that tissue

Question 14

What is the difference between ischemia and hypoxia?

Answer 14

Hypoxia is inadequete blood oxygenation such as in Asthma, COPD
Ischemia is lack of blood supply to a certain site such as in blood clots or injury

Question 15

What are the two types of cell death and how are they different?

Answer 15

Necrosis
- primarily pathologic and associated with inflammation
Apoptosis
- usually physiologic without associated injury, can still be pathologic though

Question 16

What are the characteristics of necrosis?

Answer 16

Enlarged cell with nucleus pyknosis, karyorrhexis, karyolysis
Disrupted plasma membrane
Enzymatic digestion/leaking out of cell (Troponin)
Frequent surrounding inflammation
Pathogenic

Question 17

What are the characteristics of apoptosis?

Answer 17

Reduction in size of the cell
Fragmentation of the nucleus, membrane remains intact
Contents of cell intact and released as apoptotic bodies
No inflammation
Usually physiologic, but sometimes pathologic

Question 18

What are the characteristics of reversible changes?

Answer 18

Fatty Change, lipid vacuoles in cytoplasm, usually occurs in cells with lipid metabolism ie. Liver
Cellular Swelling, membrane blebs/distended ER
Example: Cirrhotic Liver

Question 19

What point does the cellular changes become irreversible?

Answer 19

When the organelles and cell membrane rupture

Question 20

What are common causes of these type of reversible changes?

Answer 20

Alcohol, Obesity, Anorexia, DM, viral infections

Question 21

Why does the liver become fatty with chronic alcohol use?

Answer 21

• impairment of microsomal and mitocondrial functions (where fat is broken down)
• decreased fatty acid oxidation
• increased fatty acid metabolism from peripheral

Question 22

What are the most common types of necrosis?

Answer 22

Coagulative
Caseous
Liquefactive
Fat
Gangrenous
Fibrinoid

Question 23

What kind of necrosis happens to solid organs after anoxia or ischemia?

Answer 23

Coagulative

Not the brain though

Question 24

What kind of necrosis has complete digestion of tissue dissolved by hydrolytic enzymes?

Answer 24

Liquefactive Necrosis, – Known as Abscess
ie. Pyelonephritis
Most common with bacterial and fungal infections
(Brain undergoes this necrosis after infarction)

Question 25

What necrosis type of necrosis is used to describe coagulative necrosis in distal extremities?

Answer 25

Gangrenous Necrosis
Wet = infected as well
Dry = noninfected

Question 26

What type of necrosis has loss of cell outlines and surrounded by inflammatory cells?

Answer 26

Caseous Necrosis, which is typical of TB granulomas

Question 27

What kind of necrosis can occur with chronic alcoholism and pancreatitis?

Answer 27

Fat Necrosis, build of fat on fatty organs

–Also repeated trauma to fatty tissue–

Question 28

What kind of necrosis occurs in result to deposits of immune complexes on vascular walls?

Answer 28

Fibrinoid Necrosis - is Vasculitis syndromes

Question 29

What are common mechanisms of injury to a cell?

Answer 29

• Mitocondrial damage, deplete ATP
• Increased membrane permeability
• Increased ROS and DNA damage
• Increased Ca+2 causing inapproriate activation/inactivation

Question 30

What are two results of depleted ATP?

Answer 30

• cellular and organelle swelling due to influx of cations

- clumping of chromatin due to lowered pH because of glycolysis producing acid

Question 31

What is a key result of mitocondrial injury?

Answer 31

Leaking and production of ROS and pro-apoptotic proteins

Question 32

What factors contribute to cellular injury?

Answer 32

Type of injury, hypoxia or ischemia
Duration of injury
Severity, partial or complete ischemia
Type of cells affected (neuron>cardiac>skeletal)

Question 33

What is reperfusion injury?

Answer 33

When there was ischemia and flow is restored, which causes a large influx of ROS causing additional cellular damage + inflammatory response = further damage

Question 34

What are the typical signs of apoptosis of a cell?

Answer 34

• Reduction in size
• Cellular contents do not leak
• No inflammation

Question 35

What are common physiologic reasons of apoptosis?

Answer 35

embroyogenesis, elimination of T-cells, death of inflammatory cells, etc

Question 36

What are the causes of apoptosis of cells?

Answer 36

• DNA damage from radiation/chemo
• accumulation of misfolded proteins, Alz disease
• Viral infection damage
• organ atrophy due to obstruction

Question 37

What are the morphologies of apoptosis?

Answer 37

• Cytoplasmic eosinophilia
• Condensation of chromatin
• cell shrinkage
• cytoplasmic blebs
• phagocytosis without inflammation signs

Question 38

What are the two pathways for apoptosis?

Answer 38

Intrinsic, Bcl-2 proteins induce mito to release pro-apoptotic factors cytochrome-c activating caspases
Extrinsic, Death receptor, activating caspases

Question 39

What are the characteristics of dystrophic calcification?

Answer 39

Build up of calcium in non-viable and damaged tissue
Normal body calcium levels, white gritty deposits
Basophilic, blue color stain
Common Locations: Aortic valves, vessel lumens, lymphnodes

Question 40

How is metastatic calcification different than dystrophic?

Answer 40

• Normal tissues will be effected due to body having hypercalcemia. Increased PTH, Vit D, causing renal failure and destruction of bone.
  Locations: lungs, kidney, gastric tissues

Question 41

How do cells undergo aging?

Answer 41

Chronic nonlethal damage over time, ROS damage, progressive shortening of telomeres.
Decreased cellular survival and homeostasis