d interstitial fluid. Plasma proteins have specific functions; some act as escorts for lipids because lipids are insoluble in water and therefore can only travel in the blood stream when bound to proteins. Immunoglobulins are another class of proteins that serve as antibodies to help combat viruses and foreign matter that enters the body. Other proteins called fibrinogens help seal blood vessels when they are injured. (Biology)
             Along with proteins blood plasma contains two types of cells: red blood cells and white blood cells. Red blood cells (RBCs) transport oxygen to other cells in the body while white blood cells (WBCs) are what help in defending the body against viruses and foreign matter that enter the body. Platelets are also found in blood plasma, they are pieces of cells that help in blood clotting. (Biology)
             Red blood cells are also called erythrocytes and are the most numerous of the blood cells. There are about 5 to 6 million RBCs found in each cubic millimeter of human blood and about 25 trillion found in 5 liters of human blood. These cells are very special because their structure is designed so that they are more efficient in their task of carrying nutrients and oxygen to cells and collecting wastes to dispose of them. Erythrocytes are biconcave disks, meaning the center of the disk is thinner than the edges. The unusual characteristic of erythrocytes is that they lack a nucleus. Also, all RBCs lack the mitochondria that produce ATP, instead they generate their ATP through anaerobic metabolism. Erythrocytes use anaerobic metabolism because their main function is to transport oxygen, if the RBCs used the oxygen they carried then they would not be as efficient. (Biology)
             White blood cells is the name for the collective group of five major types: monocytes, neutrophils, basophils, eosinophils, and lymphocytes. All these cells work to fight infections in several ways. White blood cells are also called leukocytes and ...