13/11 weekend

Question 1

What is Inflammation?

Answer 1

Inflammation is a response of vascularized tissues that delivers leukocytes and molecules of host defense from the circulation to the sites of infection and cell damage in order to eliminate the offending agents.

Or simply: The response of living tissues to injury

Robbins & Cotran Pathologic Basis of Disease, Tenth Edition

Question 2

Basic sequence of events in an inflammatory reaction?

Answer 2

Histamine = example of vasoactive amine

Question 3

Causes of inflammation?

Answer 3

Foreign bodies
Tissue necrosis
Infection
Immune reactions (Hypersensitivity)

Hypersensitivity= reactions in which the normally protective immune system, is inappropriately activated and damages the individual’s own tissues. Hence inflammation is inappropriately activated and is a major cause of tissue injury in these diseases.

Question 4

Hypersensitivity?

Answer 4

Are essentially injurious immune reactions to the individual, elicited by exogenous antigens or endogenous self-antigens.
Involves two stages: sensitization and effector stage.

Question 5

Type 1 Hypersensitivity?

Answer 5

Immediate, or type I, hypersensitivity is a rapid immunologic reaction occurring in a previously sensitized individual that is triggered by the binding of an antigen to IgE antibody on the surface of mast cells.

IMMEDIATE
E.g. Allergies, anaphylaxis

Question 6

Type 2 hypersensitivity?

Answer 6

IgG/IgM antibodies that react with antigens present on cell surfaces or in the extracellular matrix cause disease by destroying these cells, triggering inflammation, or interfering with normal functions

e.g.autoimmune diseases; myasthenia gravis, Hemolytic disease of newborn

IMMEDIATE

Question 7

Type 3 hypersensitivity?

Answer 7

Antigen-antibody (IgG/IgM) complexes [immune complexes] produce tissue damage mainly by eliciting inflammation at the sites of deposition.

IMMEDIATE

Antigens are typically free floating, once immune complex formed they deposit.
E.g. Serum sickness, Arthus reaction

Question 8

Type 4 hypersensitivity?

Delayed or immediate response?

Answer 8

Cell-mediated hypersensitivity is caused mainly by inflammation resulting from cytokines produced by CD4+ T cells. Other mechanism is CD8+ T Cell–Mediated Cytotoxicity.

DELAYED (after a day)

e.g. TUberculosis skin test, Contact dermatitis

Question 9

Autoimmune disease?

Answer 9

Immune reactions against self antigens.

(I guess its a type of hypersensitivity disease)

Question 10

T helper cell another name?

Answer 10

CD4+ T cell = T helper cell

Question 11

T killer cell another name?

Answer 11

CD8+ T cell = T killer cell

Question 12

Stages of acute inflammation?

Answer 12

(1) dilation of small vessels leading to an increase in blood flow; (2) increased permeability of the microvasculature enabling plasma proteins and leukocytes to leave the circulation; and (3) emigration of leukocytes from the microcirculation, their accumulation in the focus of injury, and their activation to eliminate the offending agent

VASCULAR PHASE- changes in blood flow. Accumulation of exudate
CELLULAR PHASE- Delivery of neutrophils

Question 13

In acute inflammation what induces vasodilation

Answer 13

Vasoactive amines= histamine

Question 14

In acute inflammation what induces increased vessel permeability?

Answer 14

It is elicited by histamine, bradykinin, leukotrienes, and other chemical mediators.
Leads to increased interendothelial spaces.

Question 15

WIth regards to acute inflammation is the oedema fluid exudate or transudate?

Answer 15

Exudate, as increased vascular permeability leads to protein rich fluid.