Term
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Definition
-Inflammation: the local response to irritation or injury, which includes the following components:
1.vascular changes (permeability & leakage)
2.cellular activity
3.regulation by cytokines
*inflammation is a protective mechanism whose purpose is to dilute, isolate and destroy the causes of injury and to repair tissue damaged by that injury.
-acute phase response: a systemic response in the first few days of severe injury or inflammation
1.fever
2.increased plasma protein synthesis
3.leukocytosis
a. increased No = bacterial
b. increased Eo = hypersensitivity, parasites or asthma
4.increased muscle protein breakdown to supply AA's
5.hypertension, shivering, chills and anorexia.
-5 classical signs of inflammation:
1.redness
2.swelling
3.pain
4.loss of function
5.heat |
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Term
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Definition
1.Peracute(secs-mins): early injury, before the arrival of neutrophils.
2.Acute(mins-48hrs): arrival of No
a.increased vascular permeability
b.vasodilation
c.edema
d.fibrin
3.Subacute(3-4 days): phase between acute and chronic.
a.No, macrophages, WBC's
b.increased permeability
c.endothelial hypertrophy + hyperplasia
d.edema
e.fibrin
4.Chronic(1 week - years): repair phase
a.Macrophages, WBC's, plasma cells, No
b. new blood vessels
c.collagen |
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Term
Cells involved in Inflammation
General |
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Definition
Neutrophils, monocytes, mast cells, eosinophils, basophils and platelets are all produced by precursor cells in the bone marrow and released into circulation where they:
a.circulate until they die OR
b.until they receive the signal to emigrate.
-Lymphocytes (B cells and T cells): form within lymphoid organs such as:
1.thymus
2.lymph nodes
3.spleen
4.Bursa of Fabricious (birds) |
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Term
Cells involved in Inflammation
Neutrophils (PMN's) |
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Definition
phase: acute
lifespan: 24-48 hours
weapons:lysosomal granules, plasminogen activators and bactericidal factors.
- They are the first to arrive to the area of injury
-There are many of them, especially if there's bacteria
-They surround the focus of infection
-kill by phagocytosis
-Neutrophil death releases enzymes responsible for:
a.formation and destruction of chemical mediators
b.liquefaction of cellular debris and fibrinous exudate |
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Term
Cells involved in Inflammation
Monocytes/Macrophages |
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Definition
Phase:sub-acute->chronic
Lifespan: long-lived (days->years), can replicate in the tissue
weapons: phagocytosis, enzyme production, cytokines and growth factors.
-much less common in blood
-migrate slowly and respond to different chemotactic factors
-arrive a day or so later than No
-most macrophages at the site are derived from blood moncytes, however there are some that reside in the tissues normally, they have different names: ex. kupffer cells -liver sinusoids.
-monocytes become macrophages once they leave the blood
-Normal functions of macrophages:
1.degradation of aged cells/fibrin
2.removal of necrtic debris
3.process antigens (aquired immunity)
4.contain indigestible debris
5.phagocytsis/degredation of microbes
6.secretion of cytokines and mediators |
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Term
Cells involved in Inflammation
Mast cells |
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Definition
phase:acute->chronic (associated with parasites)
lifespan:long
weapons:histamine, prostaglandins and leukotrienes, proteases that cleave compliment, No and Eo chemotaxis, lysosomal enzymes.
-they are fundamentally secretory cells that occur normally in the tissue.
-have a high affinity for IgE receptors which cause degranulation via cross-linking IgE with antigens (pollen, allergens and parasites)
-release of histamine and leukotrienes causes smooth muscle contraction and Eo recruitment. |
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Term
Cells involved in Inflammation
Eosinophils |
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Definition
phase:acute->chronic
lifespan:bloodstream circulation =5-24 hours
tissues =4-12 days
weapons:granules containing major basic protein (MBP), eosinophilic cationic protein (ECP) and eosinophilic peroxidase (EP).
-MBP= cytotoxic to helminthes and activates compliment.
-ECP= forms holes in helminthes
-EP=forms hypochlorous acid which kills microbes and tissues
-they play a role in parasite infection and allergic reactions
-they have a close relationship with mast cells |
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Term
Cells involved in Inflammation
lymphocytes |
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Definition
phase:chronic
lifespan:short to long lived
weapons:cell-mediated immunity, Ab production(plasma cells)
-along with macrophages they are the main leukocytes in chronic inflammation
-migrate towards chemokines and chemotaxins (tumor necrosis factor and interleukin-1) which are prouced by macrophages at the site of injury.
-T-cells become activated at the site by APC's
-activated T-cells then produce cytokines which activate macrophages
-B-cells will become plasma cells in the presence of chronic infections by an Ag in order to produce Ab's |
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Term
Cells involved in Inflammation
Platelets |
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Definition
phase:acute
lifespan:10 days in blood
weapons:intravascular histamine secretion, serotonin, clotting factors |
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Term
Cells involved in Inflammation
Fibroblasts |
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Definition
phase:chronic
lifespan:long
weapons: walling off infection and scar tissue formation
-found during late tissue repair
-produce new collagenous connective tissue
-arise from undifferentiated mesenchymal cells
-at the site of inflammtion they multiply rapidly and secrete globular proteins which ppt out collagen
* tissues lost due to necrsis can only be replaced by replicatino of remaining viable epithelial cells or by fibrous repair
-fibroplasia is mediated by:
a.interleukin-1
b.fibroblast growth factor
c.platelet derived growth factor |
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Term
| Inflammatory Exudates: General |
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Definition
-consist of multiple elements:
a.cells
b.proteins
c.fluid
Descriptions:clear to cloudy, watery to viscous and colorless to brightly colored:
a.red- hemorrhage
b.yellow- jaundice
* transudates are caused by hydrostatic imbalance whereas exudates are caused by inflammation
-Functions:
1.prevent bacterial spread by producing a WBC barrier between normal and infected tissues
2.destroy bacteria- hostile environment
3.cytokine formation
4.removal of necrotic debris by phagocytosis
5.liquefy clotted fibrin by release of lysosomal enzymes from No granules |
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Term
| Inflammatory Exudates: Serous |
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Definition
-clear, watery and composed of serum from the blood.
*difficult to differentiate from transudate by looking at it
-usually occurs in lined body cavities
-act to dilute noxious substances
-contain Ab's to fight infection
-good medium for bacterial growth
-examples:
a.skin blister
b.mucosal blister
c.joint swelling |
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Term
| Inflammatory Exudates: Fibrinous |
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Definition
-occurs when there is vascular damage and leakage of fibrinogen
-fibrin is pale, tan and friable
-contains: fibrin, serum, No's
-often found on mucous and serous membranes especially in the pleural, pericardial and mesenteric surfaces.
-may give a slightly granular look to a smooth, shiny surface.
-can form a pseudmembrane: a dense and tough layer of fibrin that forms a white or yellowish sheet over the damaged surface.
-can also combine to form:
a.serofibrinous exudate
b.fibrinopurulent exudate
-examples:
1.post-surgical inflammation
2.early peritonitis
3.pleuritis and pneumonia
4.Salmonella spp in the GIT
**Diptheritic inflammation: describes a circumstance where the fibrinous exudate is s firmly attached that when it is torn off (fibrinolysis not possible) it removes a bleeding superficial layer. Usually occurs in tubular organs (ie airways and GIT) |
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Term
| Inflammatory Exudates: Purulent (pyogenic, suppurative) |
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Definition
-an exudate that contains No which form pus.
-typically cream colored and viscous but can be watery or it may be inspissated and semi-solid.
-examples:
a.abcess
b.any condition with a "pyo" prefix (pyometria, pyothorax)
*abcess is a well defined collection of purulent exudate that is usually walled off by a fibrous capsule. It can burst out int surrounding tissues along lines of least tension (sinus tracts) |
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Term
| Inflammatory Exudates: Catarrhal (mucoid) |
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Definition
-characteristic component is mucous which comes from cells rather than from the blood.
-occurance is generally limited to mucous membranes, in particular the GIT and respiratry tract.
-appearance is a thick, slimy, clear to opaque fluid clinging to a mucous membrane.
-mucous acts to trap bacteria, stimulate cilia and contains Ab's (IgA) and lysosymes
-irritants are generally mild and short in duration:
a.bacterial or viral infection of lw virulence or in early phases..ex. runny nose
b.mildly irritating chemicals
-mucopurulent- Pus + mucous exudate |
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