Inflammation PDF

Definition Inflammation is a defensive process that a living body initiates against local tissue damage. Etiology of Inflammation Physical agents: extreme temperatures, electric shock, radiation, mechanical injures, etc. Chemical agents: like acids, alkalis, drugs. Biological agents: Microo...

Definition Inflammation is a defensive process that a living body initiates against local tissue damage. Etiology of Inflammation Physical agents: extreme temperatures, electric shock, radiation, mechanical injures, etc. Chemical agents: like acids, alkalis, drugs. Biological agents: Microorganisms (bacteria, viruses, fungi), parasites (helmints, insects), immune cells and complexes Cardinals sign 1-rubor ( redness) 2-dolor (pain ) 3-calor (heat) 4-tumor ( swelling) 5-functiolaesa(loss of function) Component of inflammation: 1- Vascular changes A- After transient vasoconstriction (lasting only for seconds), arteriolar vasodilation occurs, resulting in locally increased blood flow. B- The microvasculature becomes more permeable, and protein-rich fluid moves into the extravascular tissues. C- This causes the red cells in the flowing blood to become more concentrated Lead to stasis develops, leukocytes (principally neutrophils) begin to accumulate Cellular event: Deliver leukocytes to the site of injury Leukocytes ingest offending agents, kill bacteria and other microbes, and eliminate necrotic tissue and foreign substances. A- Leukocyte Recruitment Margination B- Chemotaxis. C-Leukocyte Activation D- phagocytosis : E- intracellular microbial killing : The type of emigrating leukocyte varies with the age of the inflammatory response and with the type of stimulus. In most forms of acute inflammation, neutrophils predominate in the inflammatory infiltrate during the first 6 to 24 hours and are replaced by monocytes in 24 to 48 Type of inflammatory cells : 1- neutrophil : acute inflammation during the first 24-hours.important cause of neutrophilia bacterial infection and infarction After 2-3 days neutrophil are replaced mainly by 2- monocytes-macrophages :are capable of engulfing larger particle , Important cause of monocytosis.TB, Typhus ,brucellosis 3- lymphocyte : most prominent in many viral infection 4- eosinophils: are prominent in allergic reaction and parasitic infection 5- mast cells and basophils :  Outcome of acute inflammation 1- Resolution: Regeneration and repair. When the injury is limited 2- tissue destruction and persistent acute inflammation A-Abscess; this is a cavity filled with pus( neutrophils ,monocytes and liquefied cellular debris),Its often walled off by fibrous tissue and is relatively inaccessible to the circulation),Its usually caused by bacterial infections ,often by staphylococci B-Ulcer :this is loss of surface epithelium ,this can be caused by acute inflammation of epithelial surface ( e.g peptic ulcer and ulcer of the skin ) C-Fistula: this is an abnormal communication between two organ or between an organ and a surface 3- Chronic inflammation if the offending agent is not removed, or or immune responses to self- antigens). 4-Scar: this is the final result of tissue destruction with resultant distortion of structure and in some cases altered function SYSTEMIC EFFECTS OFINFLAMMATION 1- fever 2-leukocytosis The leukocyte count usually climbs to 15,000 to 20,000 cells/mL, 3-Other manifestations of the acute-phase response include increased heart rate and blood pressure; decreased sweating, mainly as a result of redirection of blood flow from cutaneous to deep vascular beds, to minimize heat loss through the skin; and rigors (shivering), chills (perception of being cold as the hypothalamus resets the body temperature), anorexia, and malaise, probably secondary to the actions of cytokineson brain cells.  Chronic inflammation − lasts from a few months up to tens of years − alternating exacerbations and remissions Q- talk briefly about the following 1- definition of inflammation and important cause of acute inflammation 2- out come of acute inflammation 3- defined abscess 4- mention briefly disease associated with arise of chronic inflammation 5- mention briefly systemic effect of inflammation