Flashcards in Inflammation Deck (45)
What is inflammation?
The local physiological response to noxious stimuli, such as: infection and/or tissue injury. Manifestation of disease, not a disease.
What is acute inflammation?
The initial response to noxious stimuli.
List 4 features of acute inflammation.
1) sudden onset
2) short duration
3) usually resolves
4) neutrophils are the main cell involved
List 6 causes of acute inflammation.
1) microbial infection
2) bacterial toxins
3) tissue necrosis
4) hypersensitivity reaction
5) physical agents, e.g. trauma or temperature
6) chemical agents, e.g. corrosives or reducing agents
List 3 processes of acute inflammation.
1) increased vascular diameter
2) increased vascular permeability
3) formation of cellular exudate
List 4 outcomes of acute inflammation.
3) repair and reorganisation (necrosed tissue --> granulation tissue)
4) chronic inflammation
(persistence of stimuli)
What happens during reorganisation? (4)
1) macrophages phagocytose dead tissue and acute inflammatory exudate
2) granulation tissue (vascular connective tissue) fills the damage site
3) fibroblasts in granulation tissue produce collagen
4) fibrous scar tissue forms
What is chronic inflammation?
Long term inflammation.
List 4 causes of chronic inflammation.
1) primary chronic inflammation
2) progression of acute inflammation
3) recurrent acute inflammation
4) transplant rejection
List 4 features of chronic inflammation.
1) slow onset / progression of acute inflammation
2) long duration
3) may never resolve
4) macrophages, lymphocytes and plasma cells are the main cells involved
List 3 functions of neutrophils.
Involved in acute inflammation.
2) secrete granules
3) secrete cytokines
List 2 functions of macrophages.
Involved in chronic inflammation.
2) antigen presentation
List 3 things macrophages phagocytose.
1) inflammatory exudate
2) damaged cells
3) necrosed cells
List 2 functions of B lymphocytes.
1) antigen presentation
2) secrete antibodies - plasma cells
What is the function of helper T lymphocytes?
Release cytokines to recruit and activate other immune cells.
List 3 functions of endothelial cells.
1) become sticky to allow inflammatory cells to adhere
2) become porous to allow inflammatory cells to pass into tissues
3) grow into areas of damage to form new capillary vessels
What is the function of fibroblasts.
Repair - synthesise collagen in inflamed areas - scarring.
What are epithelioid histiocytes?
Tissue-resident macrophages with specific features, e.g. Kuppfer cells
List 2 features of epitheliod histiocytes.
1) little phagocytic activity
2) adapted for secretion
What is a granuloma?
Collection of epithelioid histiocytes. May also contain lymphocytes and histiocytic giant cells.
How do histiocytic giant cells form?
Multiple epithelioid histiocytes trying to phagocytose the same large indigestible particulate, hence fusing into a multinucleate giant cell.
Extravascular mass of cells and fluid due to increased vascular permeability.
What do exudate contain?
High protein content.
What do exudate result in?
Formation of oedema, hence swelling.
List the 5 features of inflammation.
1) calor - heat
2) dolor - pain
3) rubor - redness
4) tumor - swelling
5) loss of function
What is the cause of rubor?
Dilation of small blood vessels in inflamed area.
What is the cause of calor?
Vascular dilation, resulting in increased blood flow causes delivery of warm blood. Only seen in peripheries.
What is the cause of tumor?
Accumulation of extravascular fluid due to exudate forms an oedema.
List 2 causes of dolor?
1) inflammatory oedema causing stretching and distortion of tissue
2) chemical mediators of inflammation induce pain, e.g. prostaglandins, serotinin and bradykinin