Which of the following statements regarding the lymphoid organs is not true?
A)The primary lymphoid organs are the bone marrow and thymus
B)The thymus secretes hormones
C)Large numbers of macrophages and lymphocytes are found in the lymph nodes and spleen
D)The tonsils act as a first line of defense against microbes in food
E)Once a lymphocyte reaches a peripheral lymphoid organ, it remains there for its lifetime

Question

Quizplus · Accepted Answer

Once a lymphocyte reaches a peripheral lymphoid organ, it does not necessarily remain there for its lifetime. Lymphocytes constantly move between peripheral lymphoid organs and circulation to survey for antigens and mount an immune response when necessary.

Which of the Following Statements Regarding the Lymphoid Organs Is