MoD 3 Chronic Inflammation Flashcards
Name 3 ways chronic inflammation can occur.
De novo
Alongside acute inflammation
Takes over from acute inflammation if the acute response can’t heal it win a few days.
In chronic inflammation, the healing process can only begin once all the inflammatory tissue has been cleared. True or False. Explain your answer.
False.
The healing process occurs simultaneously, as the granulation tissue forms.
What are the predominant cells seen in chronic inflammation and how does this differ to the acute inflammatory response.
Macrophages and lymphocytes are predominant and they form granulation tissue.
Granulation tissue is not seen in acute inflammation and the predominant cells seen there are neutrophils.
The change in cell type that is seen means that other cells are needed to carry out jobs that the neutrophils could not do.
What are macrophages called before they enter a tissue are circulating in blood?
Monocytes.
What function do macrophages carry out?
Phagocytosis
Antigen presenting to the immune system
Recruit other inflammatory cells, via secretion of chemical mediators.
Stimulate angiogenesis - critical for wounding healing (see MoD 5)
Induce cachexia and fibrosis.
What is the role of lymphocytes?
B and T.
They process antigens, secrete antibodies/cytokines(influencing other inflammatory cells)
What is the role of fibroblasts and in what way are they similar to leukocytes?
They are similar in that they move towards to the site of injury via chemotaxis, down the concentration gradient of chemoattractant.
They secrete collagen and synthesis the connective tissue that is needed for wound healing (MoD5). They can differentiate into myofibroblasts - these have the ability to contract and are needed in wound healing.
What are giant cells? Name the 3 types of giant cells and when they are seen.
A giant cell is an aggregation of macrophages that can contain 100s of nuclei at a time. They are seen in granulomatous tissue inflammation.
Langhans - DO NOT CONFUSE WITH LANGERHANS!!!!
The nuclei of the these giant cells are peripherally located and these giant cells are most typically seen in TB.
Foreign body giant cells
- the nuclei of these giant cells are randomly arranged and these are most often seen when there is a hard to digest foreign body.
Touton
- the nuclei are in a ring towards the centre of the cell. Seen in lesions where there is high fat content. Eg, xanthomas. These lesions also contain the foamy macrophages.
Name and describe some unwanted side effects of chronic inflammation.
Fibrosis and impaired function.
- cytokines stimulate fibroblasts to lay down collagen which is initially very useful. It produces a fibrous scar which is essential in wound healing. However excessive collagen can replace parenchymal tissues which leads to a loss of function.
If there is enough myofibroblasts present, excessive contraction can cause even further damage.
Eg contractions in cirrhotic liver can impair portal blood flow, resulting in ascites.
Immune response
Can get autoimmune diseases where the body attacks self cells.
What is chronic Cholecystitis and how does it come about? What does the inflammation result in?
Cholecystitis is inflammation of the gall bladder, usually due to blockage of the cystic duct by gall stones. Repeated acute episodes of Cholecystitis results in chronic inflammation of the gall bladder.
This leads to fibrosis of the gall bladder wall.
Differentiate between UC and Crohn’s.
UC Superficial Confined to colon. Distorted crypt architecture. Increased risk of colon cancer Distal colon most affected.
Crohn's Trans mural Cobblestone appearance Granulomas Crypt abscesses Bowel fistula and anal lesions are common.
What is chronic inflammation?
A chronic response to injury with associated fibrosis.
The redness and heat seen in acute inflammation is not seen but pain and swelling are still seen.
What is granulomatous inflammation?
Inflammation with granulomas.
Granulomas are a collection of macrophages (giant cells, usually langhans) surrounding a particle that it cannot breakdown. The mononuclear cells at the centre are trying to break it down. The macrophages are epitheloid cells, which are just elongated macrophages.
Seen with sutures etc.
Name and describe the two types of granulomas.
Foreign body granulomas
Contain foreign body giant cells but very few lymphocytes.
Typically seen developing around hard to digest material.
Hypersensitivity/immune type granulomas
Contain macrophages, langhan giant cells.
Undergo central necrosis - seen in TB.
Can be harmful as they occupy parenchymal space in tissues.
