MICROANATOMY

Detailed explanation-1: -Primary lymphoid organs: These organs include the bone marrow and the thymus. They create special immune system cells called lymphocytes.

Detailed explanation-2: -Lymph nodes are small, bean-shaped masses of lymphatic tissue along lymph vessels. They store lymphocytes and filter waste, bacteria and damaged cells (including cancer cells) from lymph. The lymphocytes inside the lymph nodes also attack bacteria and viruses that they find in the lymph.

Detailed explanation-3: -The medulla is the innermost layer of the lymph node and contains large blood vessels, sinuses, and medullary cords. The medullary cords contain antibody-secreting plasma cells, B-cells, and macrophages. The medullary sinuses (or sinusoids) are vessel-like spaces that separate the medullary cords.