MLT GlobeBasic Pathology: Inflammation – page 3
134 Basic Pathology MCQs on Inflammation with answers and explanations.
After leaving the circulation, leukocytes move toward the site of injury along a chemical gradient. This movement is called:
Chemotaxis is locomotion along a chemical gradient. Margination and rolling occur within vessels, and diapedesis is passage through the vessel wall.
Activation of the kallikrein system in inflamed tissue produces a peptide that directly stimulates pain fibres. It is:
Kallikrein cleaves kininogen to bradykinin, which increases vascular permeability and causes pain. Histamine mainly affects vessels.
Which inflammatory mediator is released preformed from platelets and mast cells rather than being generated from plasma proteins?
Serotonin is a stored vasoactive amine in platelet granules. Bradykinin, complement fragments and plasmin come from plasma protein cascades.
Apart from endothelial cells, which cell stores P-selectin (CD62P) in its granules and displays it on activation?
P-selectin is stored in platelet alpha granules and endothelial Weibel-Palade bodies. Leukocytes carry L-selectin instead.
Which cell expresses E-selectin (CD62E) after stimulation by IL-1 or TNF?
E-selectin is synthesised by cytokine-activated endothelium. Platelets carry P-selectin, and leukocytes carry L-selectin.
Lymph nodes draining an infected site become enlarged and tender because of follicular hyperplasia and increased cellularity. This is termed:
Reactive (inflammatory) lymphadenitis is benign node enlargement from immune stimulation. Lymphangitis involves lymphatic channels, not the node.
Which molecules mediate the first loose, transient binding (rolling) of leukocytes on endothelium?
Low-affinity selectin binding causes rolling. Integrins give firm adhesion, and PECAM-1 mediates transmigration.
As blood flow slows in inflamed venules and shear stress falls, leukocytes move out of the central stream to line the endothelium. This is called:
Margination is the peripheral repositioning of leukocytes when flow slows. Transmigration (diapedesis) and chemotaxis occur later.
Vasodilation and increased vascular permeability in acute inflammation serve mainly to:
The vascular reaction maximises movement of plasma proteins (antibodies, complement, fibrinogen) and leukocytes out of the circulation into tissue.
Granulomas that form because an agent triggers a persistent T-cell-mediated immune response, as in tuberculosis, are termed:
Immune granulomas arise when T cells and macrophages react persistently to a poorly degradable antigen, such as mycobacteria.
Which pair of phagocytes are the principal effector cells eliminating offending agents in typical inflammatory reactions?
Neutrophils and macrophages ingest and kill microbes and clear debris. Eosinophils and basophils/mast cells dominate in allergic and parasitic reactions.
Granulomas around suture material or talc, formed without a T-cell-mediated response, are termed:
Inert material too large to be phagocytosed provokes foreign-body giant cells without a specific T-cell response.
The 'lectin' in the name selectin indicates that its extracellular domain binds:
Selectins are C-type lectins that bind sugar structures (sialylated oligosaccharides) on glycoproteins.
Besides Crohn disease, which immune-mediated disorder of unknown cause classically produces non-caseating granulomas?
Sarcoidosis forms non-caseating granulomas in lymph nodes and lungs without a known agent. Tuberculosis is infectious and typically caseating.
Tissue infiltrates in IgE-mediated allergy and helminth infection are characteristically rich in:
Eosinophils are recruited by eotaxin and IL-5 in Th2 responses; their major basic protein is toxic to parasites.
Histologically, small vessels distended and packed with slowly moving red cells in an inflamed area indicate:
Increased permeability concentrates red cells and slows flow (stasis), so dilated small vessels appear packed with erythrocytes.
The warmth and redness (calor and rubor) of acutely inflamed tissue are mainly due to:
Histamine and NO dilate arterioles, increasing local blood flow and causing heat and erythema. Permeability mainly causes swelling.
Compared with a transudate, an exudate characteristically has:
Exudates arise from increased permeability and contain protein, inflammatory cells and debris, raising specific gravity.
In the inflammatory cascade, leukocytes transiently bind to and detach from endothelium via selectins, tumbling along the surface. This step is called:
Rolling is mediated by low-affinity selectin binding; integrin-mediated firm adhesion, transmigration (diapedesis) and chemotaxis follow.
A pus sample from an acute abscess in the first 24–48 hours will be dominated by which cell type?
Neutrophils are the principal leukocytes of acute inflammation, arriving early. Lymphocytes and plasma cells characterise chronic inflammation; eosinophils suggest allergy or parasites.