falls, fluid in the plasma may escape into the surrounding tissues, causing edema. Fibrinogen plays an important part in clotting. Globulin proteins, especially the gamma globulins, help fight infection (423).Red blood cells, also called erythrocytes, are the most numerous of the formed elements. Each micro liter of blood contains from four to six million red blood cells. Red blood cells are constantly circulating throughout the bloodstream. The main job of these cells is to carry oxygen from the lungs to the body tissues, and to carry carbon dioxide from the body tissues to the lungs. A mature erythrocyte has the shape of a donut without the whole. It is a flat disk with thick, rounded edges and a thin indented center. Red blood cells have no nucleus, they consist of only three parts: the cell membrane, hemoglobin, and a group of chemicals. The cell membranes main function is to act as an envelope and hold the cell together. The hemoglobin enables the red blood cells to carry oxygen. The chemicals in red blood cells provide energy and help keeps the erythrocytes in good condition. The red blood cells are produced in bone marrow (423-423). White blood cells, also called leucocytes, help protect the body against infection. A micro liter of blood contains four thousand to ten thousand leucocytes. These cells range from seven to twelve microns in diameter, and, unlike red blood cells they have a nucleus. There are several kinds of white blood cells, including: neutrophils, lymphocytes, and monocytes. Neutrophils are the most common kind of leucocytes, their main function is to fight off infection. When an infection is detected in the body, the bone marrow releases far more neutrophils than normal. The development process usually takes about twelve days, and the neutrophils leave the blood a few hours after being released from the marrow. They then move through body tissues to an area of bacterial infection. The neutroph...
