Question

Using the textbook "The Immune system" by Peter Parham please answer, What is the function of primary lymphatic tissue and how is this different than secondary lymphatic tissue?

Answer 1

Primary lymphatic organs are where lymphocytes are formed and mature. They provide an environment for stem cells to divide and mature into B- and T- cells:

There are two primary lymphatic organs: the red bone marrow and the thymus gland.

Secondary lymphatic tissue do not produce B and T-cells. Secondary lymphoid tissues are arranged as a series of filters monitoring the contents of the extracellular fluids, i.e. lymph, tissue fluid and blood. The lymphoid tissue filtering each of these fluids is arranged in different ways. Secondary lymphoid tissues are also where lymphocytes are activated.

These include: lymph nodes, tonsils, spleen, Peyer's patches and mucosa associated lymphoid tissue (MALT).