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 protein hormones,collectively called thymopoietins.
C)Large numbers of macrophages and lymphocytes are found in the lymph nodes and spleen.
D)The tonsils contain lymphocytes,macrophages,and dendritic cells that respond to microbes in food.
E)Once a lymphocyte reaches a secondary lymphoid organ,it remains there for its lifetime.

Question

Quizplus · Accepted Answer

Once a lymphocyte reaches a secondary lymphoid organ, it circulates through the bloodstream and lymphatic vessels and can leave the organ to patrol other locations in the body. Therefore, it does not remain in the secondary lymphoid organ for its entire lifetime.

Which of the Following Statements Regarding the Lymphoid Organs Is