chronic inflammation

Question 1

What is chronic inflammation? like what are its characteristics ya know?

Answer 1

• prolonged beyond weeks
• active inflammation, tissue destruction and repair
• persist until stimulus eradicated
• can be injurious
• affect tissue cannot resolve, but undergo healing

Question 2

what are the 3 causes of chronic inflammation

Answer 2

unresolved acute inflammation, prolonged exposure to toxic agents and immune mediated responses

Question 3

describe how unresolved acute inflammation leads to chronic inflammation using osteomyelitis

Answer 3

• persistent bone marrow infection
• chronic inflammatory cells stimulate bone resorption and despoit bone tissue
• can be fixed with antibiotics and surgery

Question 4

describe how prolonged exposure to toxic agents can lead to chronic inflammation in terms of prosthetics

Answer 4

wear particles released from degradation

- granulaomatous inflammation where clustered t cells activate macrophages and transform into epithelial-like cells

Question 5

describe immune mediated reaction rheumatoid arthritis

Answer 5

• own cells = foreign
• t cells activate macrophages and cytokines
• stimulate synovial cells
• pannus formation = destroy cartilage and lose joint space

Question 6

what are the main features of chronic inflammation

Answer 6

mononuclear cell infiltration
tissue destruction
attempted healing and replacing damage tissue with ct

Question 7

what are the systemic effects of chronic inflammation

Answer 7

arthralgia and myalgia 
fever 
leukopenia 
chronic fatigue + mood disorders 
GI complications

Question 8

what is the most dominant cell type in chronic inflammation

Answer 8

macrophages

Question 9

how are macrophages activated

Answer 9

signals from t helper cells (lymphocytes)

Question 10

what is the function of macrophages

Answer 10

chemical mediators, killing bacteria and cells, remove EV debris, fibrin, foregin particles, granulomatous inflammation

Question 11

what is the lifespan of macrophages and describe their maturation

Answer 11

in blood (monocyte) = 1 day 
in tissue = months -> years 
maturation mediated by growth factors, cytokines, adhesion molecules, cellular interactions

Question 12

what are the positives and negatives of macrophage activity

Answer 12

positives = increases lysosomal effects and reactive oxygen species which is toxic to microbes. also helps fibroblast proliferation and stimulates angiogenesis 
negatives = products are responsible for tissue injury and dissolution of EC matrix

Question 13

what is granulomatous inflammation

Answer 13

a focal collection of macrophages, epitheliods, and multinucleated giant cells that have amassed an indigestible substance
its a protective response that leads to tissue necrsosis because of the secretory cells

Question 14

what is a mn giant cell and what are the different types

Answer 14

its a fusion of macrophages
langhans = nuclei arranged peripherally
foreign body = indigestible material within the cytoplasm

Question 15

what are the steps of granulomatous inflammation

Answer 15

injury -> inability to digest agent -> acute failure -> persistent injury -> macrophage recruitment -> giant cell formation -> cell mediated response => granuoma

Question 16

features of lymphocytes

Answer 16

proliferate bone marrow + tissues 
long lined 
some present normally 
antigen activated
release mac act ctokines 
pos feedback loops

Question 17

features of plasma cells

Answer 17

humoral
terminally differentiated B cells
1 kind of antibody produced
common lymphoid progenitor

Question 18

features of fibroblasts

Answer 18

secrete EC matrix components

for immune and wound healing

Question 19

feature of endothelial cells

Answer 19

angiogenesis

Question 20

features of eosinophils

Answer 20

IgE mediated reactions

granules are toxic proteins

Question 21

what are the outcomes of chronic inflammation

Answer 21

if you remove stimulus = repair through fibrosis and scar formation
but healed tissue is not parenchymal tissue
often loses function
if stimulus not removed = poor prognosis, dependant on causative agent

Question 22

what are the aims of wound healing

Answer 22

remove damaged tissue
fill gap caused by tissue destruction
restore structural continuity and function if possible

Question 23

what does regenerative healing mean and what are the possibilities for labile, stable and permanent cells

Answer 23

replaced with parenchymal tissue
labile = can regenerate quickly
stable = can regenerate slowly
permanent = cannot regenerate

Question 24

name the 3 phases of wound healing

Answer 24

reactive, reparative, remodelling

Question 25

describe the reactive phase of wound healing

Answer 25

haemostasis and vascular spasm platelet coagulation and clot formation inflammation, decrase pathogens, cells migration + vasodilation (signs of acute inflam)

Question 26

describe the reparative phase of wound healing

Answer 26

``` epithelialisation = grows under the clot, separating clot and underlying tissue = bridge between wound edges granulation = fibroblasts, myofibs (like fibroblasts w/contractile potential), macs, collagen, caps, lymphatic vessels ```

Question 27

describe the remodelling phase of wound healing

Answer 27

macrophages, scar formation, realignment of tissue

Question 28

describe primary intention healing

Answer 28

wound with close edges fibroblasts and granulation tissue closure = 1 week return function with minimal scarring

Question 29

describe secondary intention healing

Answer 29

``` wound with far edges healing from bottom up loss cells and tissue inflammation is intense carries lots of necrotic debris and exudate increased granulation tissue fills until the epithelia regenerates increased collagen synthesis wound contraction is frequent scar tissue replaces normal tissue ```

Question 30

what is the function of granulation tissue

Answer 30

to protect against microbial invasion and further injury | fills base up with new tissue and vasculature and replaces necrosis until that is replaced with scarring

Question 31

what are the components of granulation tissue

Answer 31

new, thin blood vessels | fibroblasts, keratinocytes, endothelial cells, inflammatory cells phagocytose dead tissue

Question 32

what are the sequential changes of granulation tissue

Answer 32

- vascular (new caps, macs, support cells that replace area of tissue damage) - fibrovascular (fibroblasts, caps, macs) - fibrous (fibroblasts -> collagen = align and deposit increase contraction)

Question 33

stages of regenerative healing in a fracture

Answer 33

haematoma -> granulation tissue -> soft calus -> hard callus -> remodelling

Question 34

describe the haematoma an granulation tissue stage of regenerative healing

Answer 34

happens at time of fracture and severs bv and preiosteum leads to blood clot invastion of fibsm macs, oclasts + obblasts invasion turns the clot into soft fibrous mass of GT

Question 35

describe the soft callus stage of regenerative fracture healing

Answer 35

angiogenesis collagen within GT chondroblasts => patches of firbrocartilage GT gets stronger but is still malleable

Question 36

describe the hard callus stage in regenerative fracture healing

Answer 36

oblasts produce bone ring around fracture site joining ends together makes sure broken bone is immobilised and prevents reinjury or misalignment

Question 37

describe remodelling phase of regenerative fracture healing

Answer 37

hard calus = 3-4 months oclasts dissolve broken bone fragments oblasts deposit spongy bone

Question 38

describe the reactive phase of nonregenerative MI healing in terms of hours

Answer 38

6-12 = myocytes die, no macroscopic changes, high eosinophilia 12-24 hours = high eosinophilia + myocyte necrosis 24-72 = high neutrophils infiltrating tissue and removing necrotic myocytes, nuclei fade from cells (karyolsis)

Question 39

describe the reparative phase of non-regenerative healing in MI

Answer 39

3 days post MI = fibroblasts + endothelial cells infiltrate injury weeks after = GT

Question 40

describe remodelling phase of nonregenerative MI healing

Answer 40

6-8 weeks = healed myocaridum fibs lay collagen infalm cells drain via lymps mature scar

Question 41

local factors taht influence healing

Answer 41

``` infection mechanical foreign bodies vascular supply size, location, type ```