Inflammation Lecture 21.12.23 PDF

INFLAMMATION ◼ inflammation - definitions, classification, causes ◼ comparison between acute and chronic inflammation ◼ signs of inflammation, symptomatology ◼ the sequence of vascular changes and cellular changes in acute inflammation and their purpose ◼ consequences and outcome o...

INFLAMMATION ◼ inflammation - definitions, classification, causes ◼ comparison between acute and chronic inflammation ◼ signs of inflammation, symptomatology ◼ the sequence of vascular changes and cellular changes in acute inflammation and their purpose ◼ consequences and outcome of inflammation ◼ morphologic patterns of inflammation Inflammation definition Inflammation is a response to injury. = the defensive reaction of the organism to the damaging factor, the aim of which is to remove or destroy the cause of damage or to remove cells and tissues affected by necrosis.  causes, etiology of Inflammation inflamation Physical agents: extreme temperatures, electric shock, radiation, mechanical injures, etc. Chemical agents: products of metabolism, acids, alkalis, drugs, tissue necrosis Biological agents: microorganisms (bacteria, viruses, fungi), parasites (helmints, insects), immune cells and complexes  the aim of Inflammation inflammation 1.Fighting with infections / toxins 2.Wound healing 3.Restoring the integrity of tissues Once inflammation has achieved its goal of eliminating the offending agents, it also sets into motion the process of tissue repair. Repair consists of a series of events that heal damaged tissue. In this process, the injured tissue is replaced through regeneration of surviving cells and filling of residual defects with connective tissue (scarring).  steps of the Inflammation inflammatory reaction The typical inflammatory reaction develops through a series of sequential steps: The offending agent, which is located in extravascular tissues, is recognized by host cells and molecules. Leukocytes and plasma proteins are recruited from the circulation to the site where the offending agent is located. The leukocytes and proteins are activated and work together to destroy and eliminate the offending substance. The reaction is controlled and terminated. The damaged tissue is repaired.  sequence of events in Inflammation an inflammatory reaction Macrophages and other cells in tissues recognize microbes and damaged cells and liberate mediators, which trigger the vascular and cellular reactions of inflammation.  classification Inflammation ◼ SEVERAL POINTS OF VIEW ◼ length: ▪ acute × chronic (+ subacute, hyperacute) ◼ according to predominant component ▪ 1. alterative (predominance of necrosis - diphtheria) ▪ 2. exsudative (pleuritis) ▪ 3. proliferative (cholecystitis - thickening of the wall by fibrous tissue) ◼ according to histological features ▪ nonspecific (not possible to trace the etiology) - vast majority ▪ specific (e.g. TB) ◼ according to causative agent ▪ aseptic (sterile) - chemical substances, congelation, radiation - inflammation has a reparative character ▪ septic (caused by living organisms) - inflammation has a protective character  INFLAMMATION ◼ inflammation - definitions, classification, causes ◼ comparison between acute and chronic inflammation ◼ signs of inflammation, symptomatology ◼ the sequence of vascular changes and cellular changes in acute inflammation and their purpose ◼ consequences and outcome of inflammation ◼ morphologic patterns of inflammation Comparison between acute and chronic inflammation Inflammation acute vs chronic ACUTE INFLAMMATION Short-term lasting (minutes / days) Rich protein exsudate The main cell - neutrophil CHRONIC INFLAMMATION Long-lasting (days / years) Vascular hyperplasia 3 granulation tissue; scar formation The main cell - lymphocyte and macrophage  acute inflammation- Inflammation definition Rapid and sudden reaction for injury, where leucocytes are delivered to the areas of destructed tissues. The aim of lukocytic reaction is elimination of an infectious agent and organisation of nectrotic tissues.  chronic inflammation Inflammation - definition A response of prolonged duration (weeks or months) in which inflammation, tissue injury and attempts at repair coexist, in varying combinations. Inflammation what MUST be known! Inflammation exists until is eliminated the etiological factor and are inactivated inflammatory mediators Inflammation is potentially dangerous and should be restricted Therapy should be etiopathogenic  cells & molecules that Inflammation play important roles in inflammation The major participants in the inflammatory reaction in tissues are blood vessels and leukocytes. - blood leukocytes - cells of vascular wall (endothelium, smooth muscle cells) - cells of surrounding connective tissue (mast cells, fibroblasts) and connective tissue matrix - plasma proteins (kininogens, complement)  cells & molecules that Inflammation play important roles in inflammation  INFLAMMATION ◼ inflammation - definitions, classification, causes ◼ comparison between acute and chronic inflammation ◼ signs of inflammation, symptomatology ◼ the sequence of vascular changes and cellular changes in acute inflammation and their purpose ◼ consequences and outcome of inflammation ◼ morphologic patterns of inflammation  systemic Inflammation symptomatology ◼ fever (irritation of centre of thermoregulation) ▪ TNF, IL-1 ▪ IL-6 3 high erythrocyte sedimentation rate ◼ leucocytosis - increased number of WBC ▪ bacteria 3 neutrophils ▪ parasites 3 eosinophils ▪ viruses - lymphocytosis ◼ leucopenia - ▪ viral infections, salmonella infections, rickettsiosis ◼ immunologic reactions - increased level of some substances (C-reactive protein)  local clinical signs of Inflammation acute inflammation Heat Redness Swelling Pain Loss of function  INFLAMMATION ◼ inflammation - definitions, classification, causes ◼ comparison between acute and chronic inflammation ◼ signs of inflammation, symptomatology ◼ the sequence of vascular changes and cellular changes in acute inflammation and their purpose ◼ consequences and outcome of inflammation ◼ morphologic patterns of inflammation The sequence of vascular changes and cellular changes in acute inflammation and their purpose  acute inflammation Inflammation - mechanism MECHANISMS: ◦ Vascular (change in diameter, permeability) ◦ Cellular (rolling, adhesion, diapedesis)  Inflammation main events ◼ Acute inflammation has three main events: (1) Hemodynamic changes (alterations in vascular caliber that lead to an increase in blood flow) vascular (2) Increased vascular permeability (structural changes in the microvasculature that permit plasma proteins and leukocytes to leave the circulation) (3) Emigration of the leukocytes from the cellular microcirculation (their accumulation in the focus of injury, and their activation to eliminate the offending agent)  What are the steps of Inflammation the acute inflammatory response? (1) Recognition of the injurious agent (2) Recruitment of leukocytes (3) Removal of the agent (4) Regulation (control) of the response (5) Resolution  changes in Inflammation microcirculation 1st phase: - transient arteriolar vasoconstriction (sec-min) - NOT detectable in every inflammatory reaction - the noxious agent ENTERS the tissue - the