Question

 Monocytes 

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 1

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.