Which of the following is true of antigens?

A. Increased urine output:Diuretics promote renal excretion of sodium and water, leading to a noticeable rise in urine volume. This effect helps lower circulating fluid levels and reduces preload on the heart. Increased urine output is therefore an expected and intended response to these medications.

B. Lower plasma volume:By enhancing fluid loss through the kidneys, diuretics decrease overall plasma volume. Reduced intravascular volume helps lessen the workload on the cardiovascular system and supports blood pressure control. This decrease is a predictable physiological effect of diuretic therapy.

C. Decreased blood pressure:Lower plasma volume reduces venous return and cardiac output, leading to a reduction in arterial pressure. Many diuretics are prescribed specifically to manage hypertension by decreasing this circulating volume. A drop in blood pressure is therefore consistent with the drug’s mechanism of action.

D. Greater stress on the heart to provide adequate perfusion:Diuretics typically ease cardiac workload by lowering circulating volume and reducing vascular resistance. With less volume to pump and decreased pressure demands, the heart generally experiences improved efficiency.

A. Forming a large number of cytotoxic cells:Cytotoxic cells are produced by T lymphocytes, notB cells. B cells respond to antigens primarily by producing antibodies and memory cells, not cytotoxic T cells.

B. Immediately producing antigen-specific antibodies:B cells require activation and clonal expansion before producing significant amounts of antibodies. The response is not instantaneous; there is a latent period during the primary immune response.

C. Producing progeny cells that include plasma cells and memory cells:Upon activation, B cells undergo clonal selection and differentiate into plasma cells, which secrete antibodies, and memory B cells, which provide long-term immunity. This is the hallmark of the primary adaptive immune response.

D. Reducing its size:B cells do not shrink in response to antigen exposure. Instead, they proliferate and differentiate to mount an effective immune response.