inflammation & wound healing Flashcards

1
Q

inflammation can only occur in…

A

A LIVING PERSON!!!! dead tissue cannot produce and inflammatory response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

neutrophils represents ______ inflammation & lymphocytes represents __________ inflammation

A

acute & chronic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 5 cardinal signs of inflammation?

A
  1. Calor (hot)
  2. Rubor (redness)
  3. Tumor (swelling)
  4. Dolor (pain)
  5. Functio laesa (loss of function)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe why you get redness and warmth after injury, such as burning your finger

A
  1. injury creates stimulus signaling smooth muscle
  2. smooth muscle VASOCONSTRICT so initial few seconds after injury no pain, warmth or redness
  3. then VASODILATION= warmth & redness to the injured area
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe why edema occurs with injury

A

vasodilation=> increased blood flow through the capillaries which have no smooth muscle to control blood flow=> increase pressure in the capillaries.

This pressure starts forcing plasma to filter through the vessel walls = EDEMA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does the blood flow slow down?

A

because the plasma is leaving the capillaries there is increased hemoconcentration which leads to congestion & eventually Rouleaux formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Define Rouleaux formation, what does it do?

A

erythrocytes form stacks

this impedes the flow and circulation of blood, this allow the WBC to stay in the infected area, site of inflammation and not pass it from fast blood flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is pavementing?

A

When WBC’s marginate and become attached to the edge of the endothelium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the mechanism of pavementing?

A
  1. inflammation activates soluble mediators = INTERLUKINS
  2. Interlukins activate ADHESION MOLECULES on leukocytes & endothelial cells to STICK TO WALL
  3. platelets adhere to to capillary endothelial cells to clot and form FIBRIN STRANDS to help anchor the leukocytes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how long are the capillaries and venules permeable for ?

A

several hours to several days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

in acute inflammation what are most of the cells that are present?

A

neutrophils (PMNs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Fill in the blank:
As inflammation evolves, PMN’s are joined by other cells such as ____________ which becomes apparent within the first ________ hours

A

monocytes, 24

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the life span of a PMN?

A

2-4 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

with chronic inflammation what does a PMN eventually get replaced with?

A

macrophages, lymphocytes & plasma cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the phases for emigration of leukocytes?

A
  1. Adhesion of PMN to endothelium
  2. insertion of cytoplasmic pseudopods between the junction of the endothelial cells. AKA squeeze through endothelial membrane
  3. pass through basement membrane
  4. move away from the vessel toward to cause of inflammation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Define chemotaxis? What activates it?

A

active movement of PMN along a concentration gradient.

Chemotactic substances such as, bacteria or tissue destroyed by inflammation or from activated complement.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What occurs once the PMN’s reach their chemotatic substances?

A

they loose their mobility and start PHAGOCYTOSIS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the steps of phagocytosis?

A
  1. Recognition
  2. Attachment
  3. Engulfment
  4. Kill bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is attachment of the PMN to the bacteria facilitated by?

A

leukocytes have:

  • C3 receptors for COMPLEMENT
  • receptors for Fc portion of IMMUNOGLOBULINS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what is the substance released in the phagocytic vacuole to kill the bacteria?

A

bacteriocidal substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what does pus consist of?

A

dead any dying PMN’s & tissue debris

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

define suppurative inflammations or purulent

A

inflammations dominated by pus formation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the two important clinical findings that inflammation produces?

A

fever and leukocytosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is the mechanism behind a fever?

A

bacteria => triggers PMNs & macrophages => release pyrogens (interleukin I & TNF) => act as thermoregulator center in hypothalmus & release prostaglandins to mediate fever

when the source of inflammation is gone, then interleukin I and TNF will no longer be released and therefore the fever will go down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
how many WBCs are in nl blood
less than 10,000 WBC's/mm3
26
Fill in the blank: | Mediators of inflammation act on the ______________, stimulating rapid release of _____________
bone marrow, leukocytes
27
leukocytosis is when the number exceeds...
12- 15,000
28
what areas would you look for typical signs of inflammation during a PE?
skin, eyes, oral mucosa, genital organs
29
What is the mildest form of inflammation?
Serous Inflammation: exudation of fluid that is clear like serum [Extra info] - occurs in early stages - typical of VIRAL infections (vesicles of herpes ) - autoimmune (SLE) serous pericarditis, pleuritis - 2nd degree burns-> blisters
30
Define fibrinous inflammation
exudate that is rich in FIBRIN
31
what is the largest plasma protein?
fibrinogen
32
in fibrinous pericarditis when friable fibrin between the epicardium and pericardium is separated what does it resemble?
spread it like BREAD & BUTTAAAA (butter) !!!!! YUMYUMYUMYMUYMU
33
What types of infection is fibrinous inflammation seen in?
bacterial such as strep throat and PNA
34
describe purulent inflammation
viscous yellow fluid composed of dead PMN and necrotic tissue from pus forming bacteria (staph & strep)
35
What is a localized collection of pus with an organ or tissue ?
abscess
36
describe an abscess
central portion of purulent material surrounded by a wall composed of a capsule of fibrotic granulation tissue -tx: need to be evacuated
37
what is the difference between an abscess and a sinus?
- an abscess is enclosed cavity in the tissue | - a sinus is when the cavity forms a tract to the surface of the body
38
large abscess can also form fistulas which are...
channels formed between two preexisiting cavities or hollow organs and the surface of the body. -can be formed between two loops of bowel, fused together by inflammation
39
What can cause fibrinous pericarditis?
infection, prior surgery
40
define ulcerative inflammation & give an example
inflammation of the body surfaces or the mucosa of hollow organs Ex. stomach or intestine may result in an ulcer or loss of epithelial lining. PEPTIC ULCERS
41
define an ulcer
defect involving the epithelium but may extend into the deeper connective tissues
42
what is a form of ulcerative inflammation that is combined with fibrinopurulent exudation?
pseudomembranous inflammation
43
what forms a pseudomembrane?
exudate of fibrin, pus, cellular debris, and mucous forms on the surface of ulcers -it can be scraped away to expose ulcerated defects that bleed profusely
44
Give an example of pesudomembranous inflammation
pseudomembranous colitis from C. Diff. (Gram +) -caused by bacteria overgrowth from broad spectrum abx
45
Throw back: Best example of a fistula and fistula formation is ...
Crohns Disease it is transmural- it is all the way through. so when two loops of small bowl touch it can form a fistula through each bowel
46
Throw back: What is an organism that forms an abscess in the lungs?
gram postive cocci in grape like clusters- Staph aureus
47
Define granulomatous inflammation
special form of chronic inflammation that typically is not preceded by an acute, PMN mediated inflammation
48
Throw back: for a bleeding gastric or duodenal ulcer to form has to extend into
the submucosa where all the blood supply is
49
TBT: What meds can you give to tx pseudomembranous colitis from C.Diff?
Flagel & Vancomycin
50
TBT: Inside pseudomembranous colitis is not the organism but it is the...
Toxin (A or B) which can be tested from a stool sample
51
what causes granulomatous inflammation?
antigens that evoke a cell mediated hypersensitivity reaction or by antigens that persist at the site of inflammation
52
give an example of prototype granulomatous disease
TB
53
acute inflammation may heal without complication except when...
considerable destruction of tissues -complete healing may be postponed or never accomplished
54
stable cells can enter into the cell cycle and become...
actively mitotic where they enter mitosis, divide and replace the loss
55
The heart does not repair by functional myocytes, it heals with...
fibrosis
56
continuously dividing cells are ...
labile cells. divide through entire lifespan and can give rise to more differentiated cells also known as.. STEM CELLS!!!!
57
What are examples of labile cells?
stem cells, hair follicles, skin cells, intestinal cells, endometrium, bone marrow cells -RBC live 120 days and new ones come from bone marrow
58
what are quiescent cells?
STABLE CELLS! dont divide regularly, can stimulate division if necessary
59
Where can stable cells be found?
parenchymal organs such as liver or kidneys. partial hepatectomy stimulates remaining liver cells to enter mitosis, divide and replace the loss, once regenerated it becomes stable and stop dividing
60
what are nondividing cells?
PERMANENT cells. they do not have the capacity to proliferate under any circumstances
61
What are examples of nondividing cells?
neurons, myocardial cells
62
how do myocardial cells repair itself?
FIBROUS SCARRING!!!!
63
how do brain cells repair itself?
gliosis
64
what are the most important cells that are involved in wound healing? whats the mechanism?
Leukocytes, macrophages, connective tissue cells and epithelial cells PMN briefly scavenge the site, macrophages stay at the site and produce factors and mediators that act on connective tissue cells
65
What are the steps in healing?
1. myofibroblasts 2. angioblasts 3. fibroblasts
66
myofibroblast is composed of..
has smooth muscle cells (contracting) and fibroblasts. Contracts and brings margins together so proliferating epithelial cells can cover and restore epithelium
67
what are angioblasts?
the precursors of blood vessels that proliferate like sprouts from small vessels at the margins of the wound - appear 2-3 days after incision - 5-6th day who area is covered
68
fibroblasts are the....
cells that produce most of the extracellular matrix
69
What do fibroblasts produce?
Fibronectin- GLUE to keep everything together, provides strength to connective matrix Collagen- initially type III -> type I, and fills the gap. Fibrosis
70
what is the most common form of collagen in the body?
Type I
71
When does collagen acquire its full strength? when does that occur?
when it is laid down in the extracellular space several weeks after injury
72
What is First Intention?
wound-> coagulated blood-> scab... - scab is invaded in PMN's (scavenge debris) - 2-4 days later macrophages come and secrete growth factors and mediators - ingrowth of myofibroblasts, angioblasts & fibroblasts
73
What is granulation tissue composed of?
1. vascularized connective tissue rich in macrophages 2. myfibroblasts 3. angioblasts 4. fibroblasts
74
what is the final collagenous structure called?
SCAR!!! SIMBAAAA RAWWRRRR
75
How long does it take for the wound to transfer into the scar?
3-6 weeks
76
What occurs in order for the scar to be remodeled?
collagen is replaced by collagen that is indistinguishable from nl skin
77
What is Secondary Intention?
how the infected wound heals when there are large defects. the myofibroblasts cant contract the wound so granulation tissue remains exposed. may never completely heal
78
What are the most important determinants of wound healing?
1. site of wound: ex. skin heals well, brain does not heal at all 2. infection: sterile wounds heal faster than infected 3. mechanical factors: wounds heal faster if the margins can be moved together and site is immobile 4. Age: wounds heal faster in children than adults/elderly 5. Circulatory Status: wounds with ischemic tissue heals poorly 6. nutritional & metabolic factors: general well being promotes wound healing
79
What are complications of wound healing?
1. Deficient scar formation | 2. Excess scar formation
80
What does deficient scar formation mean? what can cause that? what can result from it?
sluggish formation of granulation tissue Cause: DM, ischemia, inadequate collagen due to corticosteroid hormones Result: scars that dont have enough strength so wound margins separate
81
what is excess scar formation?
hypertrophic scars composed by mostly Type II collagen (Keloids) results from defective remodeling of scar tissue