A. Originate from precursor cells in lymph nodes.
B. Can increase in number when their parent cells are stimulated by factors released from activated lymphocytes.
C. Unlike granulocytes, do not migrate across capillary walls.
D. Can transform into large multinucleated cells in certain chronic infections.
E. Manufacture immunoglobulin M.
Answer to the MCQ Question 8
A. False. They originate from stem cells in bone marrow.
B. True. Activated T cells release GMCSF (granulocyte/macrophage colony stimulating factor) which stimulates monocyte stem cells to proliferate.
C. False. After 4–6 days in the circulation, monocytes migrate out to become tissue macrophages.
D. True. The ‘giant cells’ seen in tissues affected by tuberculosis and leprosy.
E. False. Immunoglobulins are made by ribosomes in lymphocytes.
A. Are responsible for the major part of blood viscosity.
B. Contains the enzyme carbonic anhydrase.
C. Metabolise glucose to produce CO2 and H2O.
D. Swell to bursting point when suspended in 0.9 percent (150 mmol/litre) saline.
E. Have rigid walls.
Answer to the MCQ Question 9
A. True. Blood viscosity rises exponentially with the haematocrit.
B. True. It catalyses the reaction CO2 + H2O = H+ + HCO3–.
C. True. Glycolysis generates the energy needed to maintain electrochemical gradients across their membranes.
D. False. This is isotonic with their contents.
E. False. The walls deform easily to squeeze through capillaries.
10. Human plasma albumin
A. Contributes more to plasma colloid osmotic pressure than globulin.
B. Filters freely at the renal glomerulus.
C. Is negatively charged at the normal pH of blood.
D. Carries carbon dioxide in the blood.
E. Lacks the essential amino acids.
Answer to the MCQ Question 10
A. True. Its greater mass and lower molecular weight provide more osmotically active particles.
B. False. Only a small amount is ﬁltered normally and this is reabsorbed by the tubules.
C. True. Blood pH is well above albumin’s isoelectric point so negative charges (COO–) predominate.
D. True. As carbamino protein (R-NH2 + CO2 = R-NH COOH).
E. False. It is a ﬁrst class protein containing essential and non-essential amino acids.
11. Neutrophil granulocytes
A. Are the most common leukocyte in normal blood.
B. Contain proteolytic enzymes.
C. Have a lifespan in the circulation of 3–4 weeks.
D. Contain actin and myosin microﬁlaments.
E. Are present in high concentration in pus.
Answer to the MCQ Question 11
A. True. They comprise 60–70 per cent of circulating leukocytes.
B. True. Their granules contain such enzymes, which, with toxic oxygen metabolites, can kill and digest the bacteria they engulf.
C. False. Less than a day.
D. True. Responsible for their amoeboid motility.
E. True. Pus consists largely of dead neutrophils.