Lecture 2: Tissue Responses to Injury and Adaptations

Question 1

What are labile cells

Answer 1

Continuously cycling cells that proliferate at high rate, high regenerative capacity

Question 2

What are some examples of labile cells

Answer 2

Epithelia of the mouth, skin , gut, bladder, and bone marrow cells

Question 3

What are quiescent tissue

Answer 3

Stable cells, divide infrequently but can be stimulated to divide when the cells are lost. In Go until stimulated to G1

Question 4

What are some examples of quiescent tissues

Answer 4

Liver, renal tubular cells, fibroblasts, endothelial cells, smooth muscle cells, chondrocytes, osteocytes

Question 5

What are permanent cells

Answer 5

Non-dividing tissue that divide in embryonic and fetal life then leave cell cycle. Cells can’t be replaced when lost and have limited capacity to divide

Question 6

What are some examples of permanent cells

Answer 6

Neurons, cardiac, photoreceptors

Question 7

Is the following: normal, atrophy, hypertrophy, or hyperplasia

Answer 7

normal

Question 8

Is the following: normal, atrophy, hypertrophy, or hyperplasia

Answer 8

Hyperplasia

Question 9

Is the following: normal, atrophy, hypertrophy, or hyperplasia

Answer 9

hypertrophy

Question 10

Is the following: normal, atrophy, hypertrophy, or hyperplasia

Answer 10

Atrophy

Question 11

The left picture is normal, what tissue change is noted in right image (note: image at same magnification

Answer 11

Atrophy

Question 12

What is the mechanism of cell loss in the following atrophies: thymus involution, uterine involution after pregnancy, mammary glands following lactation, testicular atrophy in old age

Answer 12

Apoptosis- programmed cell death not pathological

Question 13

What is the pathogensis of hydronephrosis

Answer 13

1. Blockage in urinary bladder (ex: transitional cell carcinoma)
2. Block ureter outflow
3. Increase pressure on renal pelvis
4. Renal and cortical medically atrophy
5. Hydronephrosis

Question 14

What are some reasons for pathological hyperplasia and hypertrophy

Answer 14

1. Abnormal increase in functional demand
2. Excessive hormonal stimulation
3. Reactive-response to inflammation or chronic trauma

Question 15

Which image is normal and which abnormal, what is wrong with abnormal image

Answer 15

Left: normal epidermis
Right: epidermal hyperplasia

Question 16

What tissue is this? Which is normal vs abnormal? What is abnormality

Answer 16

Cardiomyocytes
Left: hypertrophic cardiomyopathy
Right: normal

Question 17

Is the following erosion and ulceration and how do you know

Answer 17

erosion because basement membrane is intact

Question 18

In terms of regeneration, what is the capacity of epithelium to response to injury

Answer 18

High regeneration capacity due to epithelial cells being labial cells that are continuously going through cell cycle

Question 19

Is this ulceration or erosion and how do you know

Answer 19

ulceration- damage the basement membrane

Question 20

Ulceration can lead to severe/acute or chronic ___ and perforated ___

Answer 20

Hemorrhage, perforated ulcer

Question 21

Does regeneration occur in ulceration injuries?

Answer 21

No, damage basement membrane with stem cells, resolution through scaring/fibrosis

Question 22

Identify which image shows erosion vs ulceration

Answer 22

Left: erosion
Right: ulceration

Question 23

What is the most common cause of stricture in the esophagus

Answer 23

Circumferential erosion or ulceration by pressure necrosis

Question 24

What is the worst outcome of ulceration in the stomach

Answer 24

Perforation leading to peritonitis

Question 25

This image shows an esophagus, what is wrong

Answer 25

ulcerated

Question 26

This image shows a stomach what is wrong

Answer 26

ulcerated

Question 27

Can the liver regenerate after an acute injury

Answer 27

Yes, quiescent cells can regenerate

Question 28

Can liver regenerate after repeated injury

Answer 28

No fibrosis will occur—> leading to modular regeneration/cirrhosis of the liver

Question 29

Identify the pathologies of the liver

Answer 29

top left: normal Bottom left: cirrhosis Top right: lipidosis

Question 30

What do both of these stains of the liver show

Answer 30

Cirrhosis—> increase in fibrosis connective tissue

Question 31

What stain stains the fibrous CT blue to identify cirrhosis of the liver

Answer 31

Trichrome stain

Question 32

How does the heart and skeletal muscle respond to reversible injury

Answer 32

Atrophy and hypertrophy

Question 33

How does the heart respond to irreversible injury? What is its regenerative capacity

Answer 33

Cardiomyocytes are permanent cells and therefore can’t regenerate—> outcome is fibrosis/scaring

Question 34

What is concentric hypertrophy

Answer 34

Thickening of the outside of the heart towards the lumen, add sarcomeres on top

Question 35

What is eccentric hypertrophy

Answer 35

Caused by addition of sacromeres to the side of the heart allowing for enlargement and dilation

Question 36

Identify the tissue type? Identify normal vs abnormal? What is causing abnormality?

Answer 36

Cardiomyocytes Left: normal Right: abnormal- myocardial fibrosis

Question 37

What are the key forms of neurological injury

Answer 37

1. Compression 2. Necrosis 3. Degeneration

Question 38

How does the brain respond to injury and heal

Answer 38

Minimal regeneration of nerve fibers or neurons, but does not heal via fibrosis but damage leaves cavitation

Question 39

Does the brain heal by fibrosis

Answer 39

No, damage results in cavitation

Question 40

What is anthracosis

Answer 40

Exogenous black pigment found in lungs as a result of air pollutants

Question 41

What does the following image of the lung show

Answer 41

anthracosis

Question 42

How is melanin formed

Answer 42

Oxidation of tyrosine

Question 43

What is the endogenous pigment lipofuscin

Answer 43

“Wear and tear” pigment, age indicator

Question 44

What does the endogenous pigment ceroid show

Answer 44

Pathogenic indicator, associated with vitamin E deficiency

Question 45

Both images show melanin pigmentation, which is benign and which is malignant

Answer 45

left: benign- look more like discoloration marks rather than masses Right: more like black masses

Question 46

What do both these histologies show? What is the difference between them and how do you know

Answer 46

both show melanin Left: malignant melanoma- can tell due to high cellular atypica Right: pigment are incontinence- benign reaction to inflammation

Question 47

Describe the mechanism in which cooper deficiency causes a fading in coat color of sheep and cattle

Answer 47

Melanin is formed by oxidation of tyrosine which requires a copper containing enzyme tyrosinase, therefore copper deficiency—> decreased melanin

Question 48

What causes jaundice coloration

Answer 48

Presence of bilirubin

Question 49

What causes hematin (brown) coloration

Answer 49

1. Artifact of Formica acid and heme 2. Liver flukes

Question 50

How would you describe this pigmentation

Answer 50

jaundice- excess bilirubin as a result of liver tumor

Question 51

How would you describe this pigmentation

Answer 51

Hematin

Question 52

What is the mechanism that normally makes us avoid gout

Answer 52

Blood uric acid uses enzyme Uricase to form Allantoin which is then excreted in urine

Question 53

How does gout occur

Answer 53

Increase in blood uric acid due to lack of uricase enzyme so not converted to allantoin

Question 54

What does the following image show

Answer 54

gout crystals

Question 55

What is the most common form of amyloid/amyloidosis in animals

Answer 55

Reactive secondary to inflammation- amyloid A deposits accumulate as acute phase proteins produced during inflammation

Question 56

Where are amyloid deposits commonly found

Answer 56

Kidney, liver, spleen, and lymph nodes

Question 57

Which image is normal? What is abnormality?

Answer 57

left: normal Right: abnormal: amyloidosis

Question 58

What is wrong here and what stain was used

Answer 58

amyloidosis identified with Congo red stain

Question 59

What is wrong here and what stain was used

Answer 59

amyloidosis identified with congo red stain that turned apple green under polarized light

Question 60

What is the difference between dystrophic calcification and metastatic calcification

Answer 60

1. Dystrophic calcification: localized increase in calcium, blood calcium levels are normal 2. Metastatic calcification: blood Ca2+ levels are increased-> hypercalcemia

Question 61

In general what is indicated by the arrows in both pictures

Answer 61

viral inclusions

Question 62

What staining technique do you want to use to identify viral inclusion bodies in lead poisoning and what tissue are they found in.

Answer 62

Acid fast Tissue: renal tubules

Question 63

what is shown here? Blood ca2+ is normal

Answer 63

Dystrophic calcification

Question 64

What is shown here? Patient was hyperglycemic

Answer 64

metastatic calcification