inflammation Flashcards
what are the 5 cardinal signs of acute inflammation?
- rubor/redness (from dilation)
- calor/increased heat (from increased blood flow)
- tumor/swelling (from acclamation of fluid)
- dolor/pain (Due to stretching and distribution of the tissues)
- functio laesa/loss of function
what are the first cells on the scene of acute inflammation? (these are the diagnostic histological feature of ACUTE inflammation)
neutrophil polymorphs
what do the neutrophil polymorphs do during acute inflammation?
- release enzymes that kill bacteria
- release chemicals that attract other inflammatory cells (macrophages)
- phagocytose pathogens
what are the 4 stages of neutrophil action in acute inflammation?
- margination - move to peripheral parts of vessels
- adhesion - adhere to endothelium
- emigration - migrate out of the vessel, into the tissue
- diapedesis -RBCs also escape from vessels passively due to hydrostatic pressure
what are the 2 types of cells you would expect to be more present in chronic inflammation?
macrophages and lymphocytes
what are the roles of macrophages?
Ingest bacteria
Carry debris
Antigen Present to lymphocytes
Secrete chemical mediators essential for chemotaxis
what are the different types of lymphocyte involved in chronic inflammation?
B - differentiate into plasma cells to make antibodies
T - provide cell-mediated immunity
what is the role of endothelial cells in inflammation?
- Become sticky in areas of inflammation so inflammatory cells adhere to them
- Become porous to allow inflammatory cells to pass into tissues
- Grow into areas of damage to form new capillary vessels
what is the role of fibroblasts in inflammation?
Form collagen in areas of chronic inflammation and repair
what is meant by acute inflammation?
A local physiological response to tissue injury. this is the initial reaction
Sudden onset
Short duration
Usually resolves
Lots of neutrophiles
what is meant by chronic inflammation?
= the subsequent and often prolonged tissue reactions following the initial response
Slow onset or sequel to acute
Long duration
May never resolve
Lots of lymphocytes
what are the 3 processes of acute inflammation?
- vessels get wider to bring blood and cells into site of inflammation
- vascular permeability and formation of fluid exudate
- permeability due to chemical mediators and vasodilation
- exudate is protein rich fluid filled with cells need for inflammation. it leaks out of the vessels causing swelling - Formation of the cellular exudate
- Emigration and accumulation of the neutrophil polymorphs into the extracellular space forms cellular exudate
what is chemotaxis?
the attraction of cells to site through release of chemicals: process by which neutrophils move to inflammation site, attracted to inflammatory mediators released
what are the 4 different outcomes that can come from acute inflammation?
- resolution - complete restoration of the tissues to normal
- suppuration - the formation of pus, a mixture of living, dying and dead neutrophils and bacteria, cellular debris and globules of lipid. leads to granulation tissue forming (scarring)
- organisation - tissue replacement by granulation tissue as part of the process of repair. (fibrosis)
- progression to chronic inflammation
give 4 examples of causes of acute inflammation?
Microbial infections e.g. viruses
Hypersensitivity reactions e.g. parasites, hay fever
Physical agents e.g. trauma/ radiation
Chemicals e.g. corrosives/ acids
give 3 examples of causes of chronic inflammation?
Autoimmunity -immune responses of an organism against its own cells and tissues
Transplant rejection
Progression from acute inflammation
what are the main differences of chronic inflammation compared to acute?
- no neutrophils
2 . less swelling because less exudate formed - Inflammation and repair happen at same time
- fibrosis (Scarring).
what are granulomas?
a collection of epithelioid histiocytes (macrophages) during chronic inflammation
how do you detect a systemic granulomatosis disease ?
- granulomas excrete ACE (angiotensin converting enzyme)
- Therefore if someone has high ACE levels in their blood, that indicates that they have a systemic granulomatosis disease
what is granulation tissue?
an important component of healing and comprises small blood vessels in a connective tissue matrix with myofibroblasts
give 4 ways to treat inflammation?
- ice it - prevents vasodilation, so less fluid leaking, so reduces swelling
- antihistamines - block histamine (a mediator)
- steroid creams - downregulate chemical mediators
- aspirin or ibuprofen -inhibits prostaglandins synthetase (prostaglandin is a chemical mediator)
what role does chemical mediators play in inflammation?
responsible for the spread of the acute inflammatory response
specifically they cause:
vasodilation, (increased blood flow)
emigration of neutrophils,
Chemotaxis,
increased vascular permeability
itching and pain
name 2 chemical mediators
histamine and thrombin
Bradykinin
NO
describe the difference in patterns of cells at acute vs chronic inflammation sites
Acute
- Polymorph neutrophils with later macrophages
Chronic
- Lymphocytes, plasma cells, macrophages
- Sometimes groups of epithelioid macrophages (granulomas)
What is the name of the cells that produce collagen in fibrous scarring?
Fibroblasts
give an example of acute inflammation
Appendicitis
give an example of a disease in which Granulomatous inflammation occurs in
Crohn’s disease
+ TB, leprosy, and sarcoidosis.
give an example of chronic inflammation
tuberculosis
give an example of chronic inflammation that wasn’t a progression of acute
Infectious mononucleosis ( a viral infection therefore not acute as more lymphocytes)
give a benefit of inflammation
Inflammation can destroy invading micro-organisms and can prevent the spread of infection.
Give a disadvantage of inflammation.
Inflammation can produce disease and can lead to distorted tissues with permanently altered function.
What are 4 systemic effects of acute inflammation?
- Fever.
- Feeling unwell.
- Weight loss.
- Reactive hyperplasia of the reticuloendothelial system.
Give examples of primary chronic inflammation
- Infective substances having resistance to phagocytosis e.g. TB, leprosy.
- Endogenous materials e.g. uric acid crystals.
What are some macroscopic features of chronic inflammation?
- Chronic ulcer.
- Chronic abscess cavity.
- Granulomatous inflammation.
- Fibrosis.
define abscess
Acute inflammation with a fibrotic wall.
