Inflammation Flashcards
What are the cellular and vascular events in inflammation
Vascular events :
1. Changes in vascular flow and caliber
2. Increased vascular permeability
3. Response of lymphatic vessels
Cellular events
1. Recruitment of leukocytes to sites of inflammation and injury
2. Phagocytosis and clearing of offending agents
Morphological types of acute inflammation
- Serous inflammation
- Fibrinous inf
- Sero fibrinous inf
4.Ulcers - Purulent inf
- Pseudomembranous inf
7.Catarrhal inf - Hemorrhagic inf
- Necrotizing inf
Fate of acute inf
Complete resolution
Healing by connective tissue replacement
Progression to chronic inflammation
Acute inflammation cells
Neutrophils
Macrophages
Eosinophils
Acute inflammation
It is a rapid often self limited response to the offending agent that are readily eliminated which develops within minutes to hours and is of short duration Characterized by exudation of fluid and plasma proteins and emigration of leukocytes predominantly neutrophils
Chronic inflammation
Inflammation of prolonged duration in which active Inflammation, tissue destruction and attempts at repair are proceeding simultaneously
Types of chronic inflammation
- Specific: it is histologically distinctive
Granuloma is the hall mark of ch specific inf
Eg. Granulomatous inflammation in TB, LEPROSY AND SYPHILLIS
Non specific: not histologically distinctive
No granuloma
Eg. Ch cholecystitis
Ch rhinitis
Ch. Osteomyelitis
Ch. Polynephritis
Ch. Gastritis
Granuloma
It is a focus of ch inflammation consisting of a microscopic aggregation of activated macrophages that are transformed into epithelial like or epitheloid cells surrounded by a collar of mononuclear leukocytes principally lymphocytes and ocassionally plasma cells
Types of grabuloma
- Pathological classification(aetiological )
Foreign body granuloma
Immune granuloma - Morphological classn
Caseating granuloma
Non caseating granuloma
Suppurative granuloma
Diffuse granulomatous inflammation
Immune granuloma causes
Immune granuloma is caused by a variety of agents that are capable of producing a persistent t cell mediated immune response.
Infectious agents: bacteria lkke m tuberculosis, m leprae
Fungi like cryptococcus neoformans, coccidiodes imitis, histoplasma capsulatum
Helminths like w. Brancrofti
- Physical agents:.
Exogenous:Talc,Silica ,suture
Endogenous: Na urate crystals
Cholesterol
Keratin
Foreign body granuloma
Incited by inert foreign bodies which induce inflammation in absence of t cell mediated immune responses
Eg . Talc sutures
Wood splinters
Histological hallmark of TB
Soft tubercle having central caseation necrosis
Chronic inflammatory cells
Mq
Lymphocyte
Mast cells
Plasma cells
Eosinophils
Resolution of acute inflammation
Removal of cellular debris and microbes by mq
Resorption of edema fluid by lynphatics
Regeneration of damaged tissues
Which type of phagocytosis is more effective
O2 dependent mechanism is more effective because it leads to formation of reactive oxygen species which are highly toxic to microbes
Whereas in o2 independent mechanism, there is activation of phospholipase enzymes which degrades the cell memb of bacteria.
Lysozyme hydrolyses the bacterial cell wall.
Why does pain occur
Because during inflammation certain chemical mediators are produced that stimulate the nerve endings
These are bradykinin
Prostaglandin
Pathways of arachidonic acid metabolism
- Cycloxygenase pathway: generates prostaglandin , prostacyclin, thromboxane A2
- Lipo oxygenase pathway- leukotreins and lipoxins
Function of each of the arachodonic acid metabolite
Vasoconstriction- pgf2a, thromboxane a2, LT C4 D4 E4
Vasodilation: PGI2, PGE1 PGE2 PGD2
increased vascular permeability: leukotriens c4 d4 e4
Chemotaxis : LK b4, lipoxins
Avascular structure which undergoes inflammation
Cornea due to infections, trauma or autoimmune diseases
Neutrophils and immune cells migrate from limbal blood vessels
Define phagocytosis
The process of engulfment of micro organism or other cells and foreign particles by phagocytes ie. Neutrophils monocytes and mq
Steps: recognition and attachment to the phagocytic receptors ie. Scavenger receptor
Mannose receptor
Opsonization
Engulfment
Killing and degradation
Oxygen dependent mechanism
Phagocytosis stimulates a burst in o2 consumption. Leads to glycogenolysis which increases glucose oxidation via hmp- shunt
Leads to production of reactive o2 species
Acute phase reactants
C reactive proteins
Serum amyloid A protein
Fibrinogen
What is an abscess?
Abscess is a localized collection of pus caused by suppuration buried in tissue, an organ or in a confined space.
They are caused by deep seeding of pyogenic bacteria into tissues
