EXAM 1: Lecture 11 - wound healing and surgical inflammation

Question 1

surgery = ____ of a wound

Answer 1

creation of a wound

Question 2

what does disruption of tissue homeostasis lead to

Answer 2

inflammation

Question 3

what is normal surgical inflammation

Answer 3

acute, local, short duration

Question 4

what is abnormal surgical inflammation

Answer 4

prolonged (chronic), severe, signs of infection, or systemic signs

Question 5

what are the 3 phases of wound healing

Answer 5

inflammation, proliferation, and remodeling

Question 6

at how many days in wound healing will you see inflammation

Answer 6

4-6 days

Question 7

at how many days in wound healing will you see proliferation

Answer 7

4-24 days

Question 8

at how many days in wound healing will you see remodeling

Answer 8

21 days - 2 years

Question 9

what is hemostasis

Answer 9

the body wanting to stop bleeding while maintaining perfusion

Question 10

what are the 2 balances of hemostasis

Answer 10

vasoconstriction and vasodilation

Question 11

what is endothelial cell disruption in hemostasis

Answer 11

immediate vasoconstriction, exposure of Von Willebrand factor (vWF) platelet activation and aggregation, and the coagulation cascade

Question 12

what happens when endothelial cells release vasodilators

Answer 12

there is vasodilation to increase blood flow

Question 13

what mediates vasodilation

Answer 13

histamine, NO, LTs, PGs, complement

Question 14

what happens when there is post-capillary venule leakiness

Answer 14

increased inflammatory cell and inflammatory mediation infiltration leading to protein leakage (edema)

Question 15

what happens with protein leakage

Answer 15

decreased osmotic pressure, increased blood viscosity, and increased interstitial pressure

Question 16

T/F: Edema facilitates delivery of soluble factors and cells and can cause pain or loss of function

Answer 16

TRUE

Question 17

what can cause vascular congestion

Answer 17

fluid loss to edema, hemoconcentration, and reduced velocity of blood flow

Question 18

what is inflammation also called

Answer 18

debridement phase

Question 19

what are the 2 phases of inflammation

Answer 19

early and late

Question 20

what happens in the early phase of inflammation

Answer 20

neutrophil recruitment

Question 21

what happens during the late phase of inflammation

Answer 21

monocyte transformation

Question 22

what are the functions of inflammation

Answer 22

prepares the body for next phases of wound healing and removes dead tissue/foreign material

Question 23

___1_ of trauma = intensity of __2___ = extent of ___3___ formed

Answer 23

1. severity
2. inflammation
3. scar tissue

Question 24

what do leukocytes do with inflammation

Answer 24

they are recruited from circulation by chemoattractants and initiate rolling, activation, tight adhesion, and transmigration of cells

Question 25

what do neutrophils do for inflammation

Answer 25

neutrophil diapedesis is encouraged by increased capillary permeability

Question 26

what is diapedesis

Answer 26

passage of blood cells through intact capillary walls

Question 27

how quickly does neutrophil diapedesis happen

Answer 27

minutes and peaks 1-2 days after injury

Question 28

why are neutrophils the first line of defense against contaminated wounds

Answer 28

they destroy debris and phagocytose bacteria

Question 29

T/F: monocytes migrate from vasculature during inflammation

Answer 29

true!

Question 30

T/F: macrophages change into monocytes

Answer 30

false, monocytes turn into macrophages

Question 31

what do macrophages do for inflammation

Answer 31

pro-inflammatory functions, stimulate proliferation of dermal/endodermal/epithelial tissues and help with remodeling phase

Question 32

how do we get resolution of inflammation

Answer 32

each of the pathways need to be halted or reversed and apoptosis of cells

Question 33

what happens if there no resolution of inflammation

Answer 33

can lead to chronic, suppurative inflammation and a non healing wound OR proud flesh in horses

Question 34

how is inflammation phase modulated by clinicians

Answer 34

1. proper surgical debridement 2. good hemostasis 3. adequate drainage 4. medications like NSAIDS or steroids

Question 35

what causes proliferation of tissues

Answer 35

fibroplasia, angiogenesis, and epithelialization

Question 36

what is fibroplasia and what does it do

Answer 36

formation of granulation tissue by fibrosis gives a temporary barrier of infection

Question 37

what are the 3 elements of granulation tissue

Answer 37

1. macrophages 2. fibroblasts 3. blood vessels

Question 38

what do macrophages do to make granulation tissue

Answer 38

debride, produce cytokines/growth factors that stimulate angiogenesis and fibroplasia

Question 39

what do fibroblasts do to make granulation tissue

Answer 39

proliferate and make new extracellular matrix

Question 40

what do blood vessels do to make granulation tissue

Answer 40

carry O2 and nutrients for cell metabolism and growth

Question 41

what day in the healing process do you start to see granulation tissue

Answer 41

day 5

Question 42

T/:F fibroblasts are directed by macrophages via cytokines and growth factors

Answer 42

true

Question 43

what is angiogenesis

Answer 43

formation of new capillaries from pre-existing vessels

Question 44

what regulates angiogenesis

Answer 44

macrophages and endothelium

Question 45

_____ tissue hypoxia = _____ vessel ingrowth

Answer 45

increased tissue hypoxia = increased vessel ingrowth

Question 46

what is epithelialization

Answer 46

when epithelium covers the wound

Question 47

what is the purpose of epithelialization and how much growth is there per day

Answer 47

it reforms barrier of infection and about 0.1-0.2mm/day

Question 48

what is wound maturation

Answer 48

continued epithelialization by thickening of the epidermis

Question 49

how do wounds contract

Answer 49

fibroblasts differentiate into myofibroblasts under influence of growth factor and cytokines

Question 50

what does remodeling mean

Answer 50

conversion of granulation tissue into scar tissue

Question 51

what does MMP stand for and what is it

Answer 51

matrix metalloproteinases it is collagenases, gelatinases, and stromelysins which is the demolition team for converting granulation in to scar

Question 52

how long does remodeling take

Answer 52

may take up 1-2 years depending on the size of the wound

Question 53

what are the 4 things that stop healing

Answer 53

1. when wound edges meet 2. tension surrounding skin > force of myofibroblasts 3. reduced numbers of myofibroblasts 4. granulation tissue is proliferative

Question 54

what is "the rude unhinging of the machinery of life"

Answer 54

shock

Question 55

what is shock

Answer 55

cascade of events that begins when cells/tissues are oxygen deprived from inadequate perfusion

Question 56

what can shock lead to

Answer 56

SIRS and MOD

Question 57

what does SIRS stand for

Answer 57

systemic inflammatory response syndrome

Question 58

is SIRS normal?

Answer 58

Yes but it is a large overreaction to the situation

Question 59

what causes SIRS

Answer 59

there are many causes leading to it. it can be infectious or non-infectious

Question 60

what are 3 things that happen with SIRS

Answer 60

cytokine storm, leukocyte dysfunction, and delayed resolution of inflammation

Question 61

what is the clinical definition of SIRS

Answer 61

must meet any 2 physiologic conditions with underlying pathologic cause

Question 62

what are the possible causes that leads to a clinical definition of SIRS

Answer 62

1. hyperthermia or hypothermia 2. tachycardia 3. tachypnea 4. leukocytosis or leukopenia 5. depression

Question 63

what causes hyperthermia (fever)

Answer 63

IL-1, IL-6, TNF-alpha, PGE2 act on the hypothalamus

Question 64

what causes hypothermia

Answer 64

shock from hypoperfusion or central blood sequestration

Question 65

what is the cascade of tachycardia

Answer 65

vasodilation to hypotension to decreased CO to increased HR

Question 66

what changes do we see on CBC

Answer 66

1. leukopenia (<48h) 2. leukocytosis (>48h) 3. left shift (variable)

Question 66

what is the cascade of tachypnea

Answer 66

hypoperfusion to anaerobic cellular metabolism to lactic acidosis to metabolic acidosis

Question 67

what causes depression

Answer 67

cytokines and eicosanoids

Question 68

what causes the stress response

Answer 68

IL-1 and TNF-alpha

Question 69

what does IL-1 and TNF-a do to cause the stress response

Answer 69

increase in adrenocorticotropic hormone to increase corticosteroids

Question 70

what do corticosteroids do to surgical healing

Answer 70

reduce it!!