chronic inflammation Flashcards
define Inflammation
a protective response involving host cells and proteins
what is the purpose of inflammation
remove the cause of injury
remove necrosis
initiate repair
what are the major differences between acute and chronic inflammation
chronic inflammation has a slow onset (days), subtle signs (autoimmune disease symptoms and mimic diseases
severe prognosis.
what are the main immune cells involved in acute inflammation
neutrophils
what are the main immune cells involved in chronic inflammation
macrophages and lymphocytes and plasma cells.
what primary causes can cause chronic inflammation
infections, endogenous material, some autoimmune, exogenous material, primary granulomatous disease.
what infections causes chronic inflammation
TB, leprosy and some viruses.
what endogenous material cause chronic inflammation
necrotic adipose tissue, uric acid crystals
what Autoimmune conditions cause chronic inflammation
rheumatoid arthritis, SLE, pernicious anaemia
what is a granuloma
collections of inflammatory cells
what conditions which involve granulomatous form cause chronic inflammation
crohns, sarcoidosis
what inflammation due recurrent acute inflammation lead to
chronic inflammation
abscess form in acute inflammation and if they are deep enough the walls what do they for,
granulation and fibrous tissue
what are the main morphological features
infiltration with mononuclear cells (macrophages, lymphocytes and plasma cells)
tissue destruction
healing and fibrosis
what are the macroscopic features of chronic inflammation
fibrous tissue extends through wall
Chronic abscess cavity
Granulomatous
what are the microscopic features of acute inflammation
Cellular infiltrate of lymphocytes, plasma cells and macrophages.
Production of new fibrous tissue from granulation tissue.
Cells in the connective tissue include: macrophages, mast cells and plasma cells (immune cells).
what is the function of macrophages
engulf and digest cellular debris and microbes
what is another name for granulocyte
Polymorphonuclear leukocytes
what granulocyte produces histamine
basophil
what molecule do injured basophils release and what is the function of this molecule
release prostaglandins
and increase blood flow to the site of infection
what is the main function of eosinophils
good antigen presenting cells.
what system are macrophages part of
reticuloendothelial system
what are macrophages in the blood called
monocytes
what is recruitment of macrophages
Macrophages already at sight of damage release cytokines which signal to monocytes
Monocytes enter damaged tissue from endothelium of blood vessel (leukocyte extravasion
what is the main role of macrophages
phagocytosis of bacteria and damaged tissue- causes tissue injury
what does low oxygen in inflamed tissue stimulate macrophages to do
induce angiogenesis, they also induce cells to re-epithelialise the wound and create granulation tissue.
what are 2 examples of bacteria that macrophages cannot kill so it holds them instead
M. tuberculosis and M. leprae.
what is granulation tissue made up from
Angiogenesis
Fibroblasts deposit collagen
Inflammatory cells
where does granulation tissue begin to grow from - the base or the apex of the wound.
The base.
define fibrosis
Formation of excess fibrous connective during repair of damaged tissue
Scarring
define a granuloma
aggregate of epitheliod histocytes and other cells, lymphocytes and histocytic giant cells.
define a histolytic giant cell
horseshoe arrangement of peripheral nuclei.
define a foreign body giant cells
large cells with randomly scattered nuclei seen in relation to foreign body material.
name 2 diseases which are granulomatous
TB and leprosy.
when does histolytic giant cells form
where material is indigestible to macrophages
They’re multinucleate giant cells. May have >100 nuclei.
Develop when 2+ macrophages try to engulf the same particle
Are histolytic giant cells phagocytic
No
Examples of granulomatous diseases
Bacterial = TB, leprosy Parasitic = schistosomiasis Fungal = cryptococcus Synthetic materials = silicosis Unknown = Sarcoidosis, crohn’s disease.
can macrophages be considered the same as histiocytes when in tissues
Yes
what organ does Tb typically effects and what it’s symptoms
Lungs
cough, haemoptysis, night sweats weight loss.
what organs does leprosy effect and what are it’s symptoms
nerve, respiratory tract, skin and eyes, loss of pain sensation and subsequent injuries, weakness. Poor eyesight.
define epithelioid histiocytes
large vesicular nuclei and eosinophilic cytoplasm (stain pink)
define silicosis
occupational lung disease from inhaling silica dust, forms scarring and granulomas
where do the granulomas form in silicosis and why is the the reason it is often mistaken for TB
upper lobes of lungs
this is where TB causes granulomas
define sarcoidosis
granulomas form in multiple organs, often lungs and lymph nodes but anywhere can be affected, usually self limiting
what are common symptoms of sacoidosis.
Fatigue weight loss joint aches and pains, cough, non specific symptoms.
which condition has caseating granulomas and which condition has non caveating granulomas
TB and crohsn
crohns non caseating
TB caseating.
what 2 factors stimulate granuloma formation in TB
Alveolar macrophages in lung release cytokines to recruit more macrophages.
Dendritic cells present antigens to T cells in lymph nodes to mount a T cell response.
define caseating
there is necrosis, epithelioid macrophages surround necrotic region that has a T cell rim.
what 2 cytokines are important in granuloma formation
TNF alpha and INF gamma
what can be seen histologically in a granuloma
Langhans giant cell -lots of nuclei
Caseous necrosis
Epithelioid macophages
what cells are involve in MS inflammation and where are they found
plasma cells and T lymphocytes are seen in white matter where macrophages break down myelin
what 2 factors mainly predispose you to chronic inflammation and give and example for each
Persistence of Infection- H pylori.
Prolonged exposure to toxic agents-Autoimmune Disease
E.g rheumatoid arthritis, Systemic lupus- inflammation anywhere.
