Three-dimensional visualization reconstructed from scanned human data of male and female figures, revealing immunological structures. The immunological system guards against invading organisms that may cause infection or disease and can be classified as either innate and adaptive. The innate system, the first line of defense, is comprised of mechanical barriers such as skin and mucous membranes, as well as chemical defenders which protect the human body from invaders. The adaptive system is composed of leukocytes, or white blood cells, which circulate in the blood vessels and destroy microorganisms that have penetrated the mechanical barriers of the body.
Immune System. Photography. Encyclopædia Britannica Image Quest. Web. 17 Nov 2011.