Practice questions

Prostacyclin (PGI2):

(Choose 2)

• A. Is synthesised by mast cells

• B. Mediates vasoconstriction

• C. Inhibits platelet aggregation

• D. Production is inhibited by aspirin

Cytokines

• Mostly act locally on the cells that produce them, and rarely at distant sites

• Have individual actions in modulating cell function, that are specific to each cytokine

• Bind to non-specific receptors on target cells

• Are involved in stimulating cell growth, but not cell differentiation

Effects of complement activation may include

• A. Opsonisation

• B. Lysis of bacteria

• C. Chemotaxis of neutrophils

• D. Haemolysis

Mechanisms of adhesions between leukocytes and endothelial cells include (choose 3)

• A. Increased binding activity of integrins

• B. L-selectin/ICAM-1 interaction in low-flow conditions

• C. Induction of endothelial adhesion molecules

• D. Redistribution of P-selectin by histamine stimulation

During the early stages of the inflammatory response, histamine-induced increased vascular permeability is most likely to occur in

• Pre-capillary arterioles

• Capillaries

• Post-capillary venules

• Veins

Chemotaxis is

• Fusion of phagosomes to lysosomes

• Attachment of mediators to extracellular material to increase phagocytosis

• Movement of cells toward a certain stimulus

• Transmigration of cells from blood vessels into tissue

A 5 year old child with recurrent bacterial infections, has analysis of peripheral leukocytes showing deficiency in myeloperoxidase (MPO). A reduction in which process is the most likely cause for the increased susceptibility to infections

• Nitric oxide (NO) production

• Lysosyme production

• Hypochlorite (H2O2) formation

• Prostaglandin production

A 65 year old woman takes ibuprofen for osteoarthritis, her pain is alleviated by reduced synthesis of the following mediators (choose 2)

• Thromboxane A2 (TXA2)

• Histamine

• Leukotriene E4 (LTE4)

• Prostaglandins

This mediator, produced by the action of lipoxygenase on arachidonic acid metabolites, is a potent chemotactic agent for neutrophils

• Prostacyclin (PGI2)

• IL-8

• Thromboxane A2 (TXA2)

• Leukotriene B4 (LTB4)

During acute inflammation, increased vascular permeability is induced by multiple mediators, including histamine released from

• Neutrophils

• Mast cells

• Macrophages

• T lymphcoytes