Leukocytes
Leukocytes are also known as white blood cells1
“including macrophages and lymphocytes, all of which develop from undifferentiated stem cells in the bone marrow. Leukocytes can leave the bloodstream and patrol the tissues, each cell producing one or more proteins capable of recognizing and binding to molecules that might signal an infection”1
Subsystems
The immune system is made up of 2 complementary systems: the humoral immune system and the cellular immune system1.
Humoral Immune System
The humoral system’s name, humor, which is latin for “fluid”1. The humoral system is directed at items int he bodily fluid, such as bacterial infections, extracellular viruses in the body fluid, and individual foreign proteins1.
Cellular Immune System
The cellular immune system is directed at host cells which have viral infections, parasites, and foreign tissues1.