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Mechanisms of Disease > Chronic Inflammation > Flashcards

Flashcards in Chronic Inflammation Deck (14):
1

What is a chronic inflammation?

Chronic Inflammation is a chronic response to injury with associated fibrosis. There is much less known about chronic inflammation and it also important to note that you rarely get one type of inflammation without the other.

2

What's the difference between acute and chronic inflammation?

Acute means rapid, immediate and short lived whilst chronic means the opposite. Chronic inflammation arises when the damage caused is too severe to be resolved within a few days or may arise de novo i.e. when the initial injury is not slight such as autoimmune conditions, chronic persistant infections, chronic low level irritation and foreign material.

3

What are the distinguishing cell types present in chronic inflammation?

1. Macrophages (monocytes in blood) large granular cytoplasm and involved in phagocytosis of pathogens and foreign bodies, antigen presenting, synthesis of: cytokines, complement system, clotting factors and proteases; and the control of other cells by cytokine release
2. Lymphocytes (sometimes called chronic inflammatory cells) both B and T involved in antibody production and perforin production
3. Eosinophils involved in allergic reactions, parasite infestations and some tumours
4. Fibroblasts and Myofibroblasts which are recruited by macrophages and make collagen for the fibrosis part of chronic inflammation

4

What are giant cells?

Giant cells are where lots of macrophages have joined to become one large multinucleate cells, usually happens due to frustrated phagocytosis

5

What are the 3 different types of giant cells and describe their appearance?

1. Langhans cells are associated with TB and look like a horse shoe shell of nuceli and a pale inside of cytoplasm
2. Foreign body type much more disorganised
3. Touton cells involved in fat degredation nuceli are still arranged in a horse show shell but have an outer covering of fat

6

What are the effects of chronic inflammation?

• Fibrosis such as ulcers and cirrhosis casuing diorganisation of architecture after attempted regernation leading to cirrhosis
• Impaired Function (rarely but sometimes increased function e.g. Graves’ disease)
• Atrophy – loss of cells
• Stimulation of immune repsonse – chronic inflammation and immunity overlap as the immune response can casue chronic inflammation and vice versa.

7

What is Rheumatoid arthritis?

Rheumatoid Arthritis – autimmune disease casuing a localised immune response casuing joint destruction and sytemic immune response as it can effect other organs and lead to amyloidosis. Usually a symmetrical disease effecting the hands and feet casuing ulnar deviation of joints in the hand. If you took a biposy it usually look like a leafy synovium.

8

What is chronic cholecystitis?

Chronic Cholecystitis – this is where a gall stone sits in the cystic gut casuing acute inflammation and ulceration. This gall stones can pop back out and in causing repetetive acute inflammation leading to chronic inflammation and fibrosis. The stone passes down the bilirary tree also casuing acute inflammation down there.

9

What is chronic gastritis?

Chronic Gastritis – inflammation of the stomach lining - casues atrophy usually of the epithelium meaning you loose the acid producing cells. Usually casued by alcohol and drugs in acute gastritis but chronic is caused by Helicobacter Pylori. Ulceration occurs because of imbalance of acid production and mucosal defence causing the damage and destruction of the Mucosa layer of the surface. If they don’t get better quickly because of the damage to the tissue this leads to scarring and fibrosis.

10

What is cirrhosis?

Cirrhosis (Liver) results most commonly from excessive alcohol consumption but also from infection and fatty liver disease. This results in fibrosis of the liver and loss of function of the liver. Liver may appear shrunken with streaks of fibrotic material and small regeneration nodules. All of this leads to cirhosis and impaired function.

11

What is granulomatous inflammation?

This is chronic inflammation with granulomas which are cohesive groups of marchophages and other inflammatory cells. Usually its formed form a center made of epithelioid histiocytes (macrophages) which are surrounded by lymphocytes.

12

What causes granulomatous inflammation to arise?

These arise where you have persistant low grade antigenic stimulation or due to hypersensetivity reactions. This includes mildly irritant foreign material, infections e.g. TB and Leprosy (mycobacterium) and some fungi. Some unknown causes are: Sarcoid, Wegner’s Granulomatosis and Crohn’s disease.

13

What are the two type of granulomas?

1. Foeign body granulomas
2. Hypersensetivity or immune granulomas e.g. caused by antigenic material

14

Describe t he granulomatous inflammation in TB?

TB casues granulomas with caseous necrosis which is the acelullar center seen on the picture to the right which looks apparently like soft white cheese. They also tend to have Langhan’s Giant cells.