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Organs Greetings, If you remember, last week we where discussing " the cells of repair" today, with your permission, we will concentrate on " the organs of repair" let's start with; THE LYMPH NODES The lymph nodes contain small lymphocytes and large dendrtic macrophages. The dendrites of the macrophages carry important impulses or messages to the cell body. The lymph stream widens very greatly as it passes through the node; therefore the rate of flow is greatly reduced. The lymph filters through a maze of passageways lined with phagocytic cells. Such cells engulf bacteria and other foreign materials from the lymph stream. Thus the body is kept in a healthy and stable condition. THE SPLEEN The spleen has 4 major functions: 1- Blood destruction- old red blood cells are destroyed in all parts of the reticuloendothelial system, including those of the lymph nodes and spleen. (Reticuloendothelial system applies to those cells scattered throughout the body that have the power to ingest bacteria and solid particles) 2- Cellular production- The spleen manufactures lymphocytes and monocytes. 3- Blood storage- The spleen serves as a reservoir for blood, or, more specifically, for red blood cells, as most of the plasma is returned to the circulation where-as red blood cells are enmeshed in the splenic pulb. Marked contractions of the spleen occurs during muscular exercise, thereby releasing red blood cells and increasing oxygen capacity. The spleen undergoes rhythmic variations in size in response to physiologic demands, such as exercise and hemorrhage, and thus influences the volume of circulating blood. The volume of stored blood may vary from a liter to as little as 50ml 4- Blood filtration- The spleen, serving as a part of the body's reticuloendothelial mechanism, filters spent cells and their debris from the blood. THE LIVER Organisms are filtered from the blood by macrophages in the wall of the sinusoids (minute blood vessels) and various toxic chemicals are removed from the blood by the liver cells. The sinusoid are lined partly by flat non phagocytic endothelial cells and partly by more rounded and irregular shaped macrophages that project into the lumen of the sinusoid. These cells are similar in structure to macrophages elsewhere and are avidly phagocytic The protective function of the liver is associated with its ability to detoxify products of catabolism, that might accumulate in dangerous proportions. These products are changed chemically into substances that can be excreted by the kidneys or through the intestinal tract. Macrophages present in the liver sirusoids aid in filtering foreign matter from the blood. Next week we will conclude the episode on the self-sufficiency of our body. See you next week, same time, same place. The Crazy Nut Team P.S. If you have missed any of the previous articles and would like to read them, please visit our archives at http://crazynut.theshoppe.com