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Video 4 Blood Composition: Components and Function

04) Blood components and function Blood is primarily a mixture of four substances: plasma, red cells, platelets and white cells. While each has very different functions, they all work together to nourish, cleanse and defend the tissue cells of the human body. Plasma is a relatively clear liquid that helps suspended cells and particles move throughout the circulatory and lymph systems as well as between these two systems. Red cells are primarily concerned with transporting oxygen molecules to tissue cells everywhere in the body where the oxygen is used as fuel. Carbon dioxide waste is created by the tissue cells, which the red cells then take from the tissue cells and carry them back to the lungs where the carbon dioxide molecules are released. Platelets are cell fragments that form clotting actions in order to plug up any breaches in the walls of the circulatory system. For example when a child scrapes a knee, the blood vessel rupture is detected by platelets, which are then attracted to the cut and clog it up, effectively patching it giving the vessels time to repair. White cells form the core of our immune system. They live in both our blood and lymph system and account for the most complex relationships of the blood. They defend our bodies from an endless supply of invaders, such as bacteria, viruses, fungus, pollens, and toxins. White cells are adaptable to new invaders and can remember those invaders, keeping specially made fighter cells in hybernation for a certain period of time. The highly specialized functions of white cells fall into five functional groups: detection, signaling the alarm, immediate on-site fighters, creating specialized fighters, destroy and eliminate. We'll learn more about each of these groups in coming videos.