Acute Inflammation Flashcards
What are the clinical signs of acute inflammation?
Calor, dalor, rubor, tumour, loss of function
What three general changes occur in acute inflammation?
Changes in blood flow, exudation of fluid, infiltration of inflammatory cells.
What changes to blood flow occur in acute inflammation?
Arterioles contract initially, then vasodilate, increased permeability of BVs, resulting in increased conc of RBC and increased viscosity of blood.
What is Diapedis? (In acute inflammation)
When a neutrophil ‘digs’ its way out of a venule. They produce collagenase, digests basement membrane
Describe the process of activation of neutrophils in acute inflammation
Chemotaxin bind to cell, triggering rush of Na+ and Ca2+ into the cell. Causes cell to reorganise cytoskeleton into triangular in direction of stimulus
What is margination of neutrophils in acute inflammation?
Neutrophils stick to walls of venules and roll along. They get stuck/adhesion…then diapedis.
What molecules are involved when neutrophils marginate during acute inflammation?
When they roll- ‘selectins’. When they stick- ‘integrins’
What happens during the recognition/attachement phase of neutrophil infiltration in acute inflammation?
Opsonins (eg IgG antibody) bind to eg bacteria make it easier to be recognised and phagocytosed.
What are the stages of phagocytosis?
Contact, recognition as foreign, engulf, internalisation (enclosed within intracellular vacuole). Then digestion from degranulation.
What are the two killing mechanisms used by neutrophils during acute inflammation?
O2 dependent (free radicals), O2 independent (uses enzymes)
What is chemotaxis?
Directional movement towards a chemical along the conc gradient
Examples of chemotaxins?
Spilled/clotted blood (thrombin), bacterial products, injured tissue
How would you differentiate between a bacterial infection and a virus through a blood test?
Bacterial infection: high levels/raised neutrophils. Viral: raised/high levels lymphocytes
Would high neutrophils suggest a bacterial or viral infection?
Bacterial
Would high lymphocytes suggest a bacterial or viral infection?
Viral infection
