RT Book, Section A1 Mescher, Anthony L. SR Print(0) ID 1208289236 T1 The Immune System & Lymphoid Organs T2 Junqueira's Basic Histology: Text and Atlas, 17th Edition YR 2024 FD 2024 PB McGraw Hill PP New York, NY SN 9781264932146 LK accessmedicine.mhmedical.com/content.aspx?aid=1208289236 RD 2024/11/03 AB The immune system provides various defenses or immunity against infectious agents ranging from viruses to multicellular parasites. Histologically, this system consists of a large, diverse population of leukocytes located within every tissue of the body and lymphoid organs interconnected only by the blood and lymphatic circulation. Immunity obviously has tremendous medical importance, one part of which focuses on autoimmune diseases in which immune cells function abnormally and attack molecular components of the body’s own organs.