Term Test 1 - Jeff

Question 1

what are the three phases of CT healing

Answer 1

inflammatory phase, proliferative phase, remodelling

Question 1

How does CT heal

Answer 1

1. fibrin scaffold (minutes)
2. necrotic tissue removed via phagocytosis and proteases from macrophages and neutrophils (days)
3. macrophages and platelets secrete chemical mediators (hours)
4. angiogenesis and fibroblasts invade along fibrin scaffold (after 2-3 days)
5. fibroblasts secrete collagen (AFTER 4-5 DAYS)
6. remodelling and contraction (weeks-months)

Question 2

formation of the fibrin scaffold occurs within

Answer 2

minutes

Question 3

by what two mechanisms is fibrin removed

Answer 3

secretion of proteases; phagocytosis

Question 4

for large wounds, what might be required to remove necrotic debris

Answer 4

debridement

Question 5

what 4 factors are released from macrophages and platelets

Answer 5

PDGF, VEGF, bFGF, TGF-β

Question 6

what growth factors stimulate angiogenesis

Answer 6

VEGF, bFGF

Question 6

what growth factors stimulate fibroblast infiltration along the fibrin scaffold

Answer 6

bFGF, PDGF, TGF-β

Question 7

fibroblasts start secreting collagen after….

Answer 7

4-5 days

Question 8

what is granulation tissue

Answer 8

tissue containing fibroblasts, new blood vessels and newly synthesized collagen

Question 9

T/F granulation tissue and granulomatous inflammation are the same thing

Answer 9

VERY FALSE

Question 10

what is the significance of 4-5 days

Answer 10

the time at which fibrous tissue is starting to be formed and we will start seeing issues such as contractures, strictures, adhesions, etc.

Question 11

what does maturing of collagen involve

Answer 11

change from type III -> type I
crosslinking

Question 12

what is responsible for contraction of wounds

Answer 12

myofibroblasts (after 4-14 days)

Question 13

wound strength (%) after:
- 3 weeks
- 6 weeks
- 6 months

Answer 13

• 3 weeks: 20%
• 6 weeks: 70%
• 6 months: 80%

Question 14

T/F after tissue injury, over time, the collagen will eventually always return to a normal histological appearance

Answer 14

F; may never return to normal appearance, but will be functional

Question 15

fibrin vs fibrous tissue

Answer 15

fibrin = polymerized fibrinogen (elastic, loosely adherent)
fibrous tissue = fibroblasts, newly synthesized bvs, collagen

Question 16

T/F fibrous tissue and granulation tissue are the same (for the sake of this course)

Answer 16

T

Question 17

granulation tissue vs granulomatous inflammation

Answer 17

granulation tissue: fibroblasts, collagen, new bvs
granulomatous inflammation: type dominated by activated macrophages, +/- giant cells, T cells and fibrous tissue

Question 18

how does EPITHELIAL tissue heal (3)

Answer 18

1. rapid sliding
2. delayed hyperplasia and migration
3. differentiation into normal epithelial phenotype (ex. stratified squamous)

Question 19

what are the requirements for epithelial tissue repair

Answer 19

1. intact CT framework
2. adequate blood supply
3. mitotically active cells

Question 20

epithelial repair takes approximately how many hours

Answer 20

24-48

Question 21

abrasion vs incision

Answer 21

abrasion only goes through epidermis; incision goes through epidermis, BM, and dermis

Question 22

would an abrasion or incision take longer to heal and why

Answer 22

incision; have to first repair the CT framework

Question 23

what are the three main reasons that epithelial tissue might fail to heal

Answer 23

1. lack of CT framework 2. no mitotically active cells 3. ischemia (loss of blood supply)

Question 24

name other reasons a wound may fail to heal

Answer 24

infection, extensive tissue damage, poor nutrient availability, movement malnutrition, corticosteroid therapy

Question 25

adverse consequences of tissue repair

Answer 25

cosmetic; impaired nutrient/gas exchange; altered organ perfusion; adhesions; stricture/contratures; impaired electrical activity

Question 26

what is ankylosis

Answer 26

joint fixation

Question 27

what is contracture

Answer 27

fixation of a joint in flexion

Question 28

collagen stains what colour histologically

Answer 28

blue

Question 29

who came up with the cardinal signs of inflammation? who added loss of function ot the list?

Answer 29

Celsus; Virchow

Question 30

what two MAIN changes define inflammation

Answer 30

1. alterations in blood vessels 2. leukocyte infiltration of tissues

Question 31

inflammation is linked with (3)

Answer 31

tissue repair, coagulation, immunity

Question 32

T/F inflammation is phylogenetically old and conserved across species

Answer 32

F; species differences but conserved otherwise

Question 33

what are 3 adverse consequences of inflammation

Answer 33

1. systemic effects (SIRS, Sepsis, APR) 2. temporary loss of function 3. scarring - permanent loss of function

Question 34

why is inflammation beneficial (2)

Answer 34

1. contain/eliminate inciting cause 2. tissue repair

Question 35

what are the 3 stages of inflammation

Answer 35

1. serous or fibrinous effusion 2. leukocyte infiltration 3. repair

Question 36

vascular changes are responsible for what cardinal signs of inflammation? (specific)

Answer 36

vasodilation: warmth, redness increased vasc. perm: swelling (edema)

Question 37

what are 4 inflammatory mediators

Answer 37

histamine, cytokines (IL-1, IL-6, TNFα), eicosanoids, complement

Question 38

what is a common source of all inflammatory mediators

Answer 38

plasma, local cells

Question 39

effects of inflammatory mediators are typically ____________ and usually ____________

Answer 39

transient; localized

Question 40

redundancy vs pleiotropy

Answer 40

redundancy: many mediators, one function pleiotropy: one mediator, many function

Question 41

what is a potential long term consequence of increased vascular permeability

Answer 41

fibrosis (due to exudation of fibrin; becomes fibrotic after 4-5 days) - subsequent issues such as stricture, adhesions, ankylosis, contractures...

Question 42

what cell produces fibrin protein

Answer 42

hepatocytes

Question 43

describe the elicitation phase of a type I hypersensitivity reaction

Answer 43

1. allergen binds IgE 2. IgE crosslinked 3. mast cells degranulate 4. release of inflammatory mediators (ex. histamine) causes immediate vasodilation and increased vascular permeability (also bronchoconstriction, pruritis) 5. late phase reaction dominated by eosinophils, macrophages, lymphocytes

Question 44

what type of T cells are involved in type I hypersensitivity (allergic reactions)

Answer 44

Th2

Question 45

give one example of allergic disease in all species, dogs, cats, horses, and cows

Answer 45

all: anaphylaxis dogs: allergic gastroenteritis cats: feline asthma horses: heaves cows: milk allergy

Question 46

neutrophil responses to inflammation only occur in (veins or arteries)

Answer 46

VEINS