Question

The primary lymphoid organs

• A. Thymus and liver
• B. Thymus and spleen
• C. Bone marrow and thymus
• D. spleen and bone marrow

Answer 1

Answer:

C. Bone marrow and thymus

• Primary lymphoid organs: These organs include the bone marrow and the thymus.

  They make special immune system cells called lymphocytes.

• Secondary lymphoid organs: These organs include the lymph nodes, the spleen, the tonsils and certain tissue in various mucous membrane layers in the body (for instance, in the bowel).