Define the term prognosis.

A. support the immune response by recognizing reoccurring antigens: Memory cells persist after an initial exposure and rapidly recognize and respond to repeat exposures, enabling a faster, stronger secondary response.
B. change into an antibody-secreting cell once activated: Memory B cells can rapidly differentiate into plasma (antibody-secreting) cells on re-exposure, but this is a consequence of their role rather than the defining reason they’re crucial.
C. bind complement to the antibody: Binding complement is a function of some antibodies (via the Fc region), not a function performed by memory cells themselves.
D. immediately secreting antibodies following the first exposure: Antibody secretion on first exposure is performed by activated naïve B cells/plasma cells; memory cells are formed after the first exposure and act on subsequent exposures.

A. myelogram: A myelogram is an imaging study in which contrast is injected into the subarachnoid space to visualize the spinal canal on x-ray/CT - it is primarily imaging, not the laboratory analysis of CSF.
B. BUN: Blood urea nitrogen is a blood chemistry test (kidney function) and does not analyze cerebrospinal fluid.
C. lumbar puncture: A lumbar puncture (spinal tap) is the procedure used to collect cerebrospinal fluid for laboratory analysis (cells, glucose, protein, culture, etc.).
D. IVP: An intravenous pyelogram (IVP) is an imaging study of the urinary tract using contrast - unrelated to CSF.