Guest guest Posted July 22, 2004 Report Share Posted July 22, 2004 Blood and All Its Parts Contents: Blood Platelets Plasma Blood Types Rh Factor Blood A human adult has about five liters of blood coursing throughout their body. The blood nourishes the body and takes away the toxins that would harm us. Without it, a human dies. Blood is alive. The cells in the blood, both red cells and white cells, are essential to the wellbeing and health of the human body. Not only do they feed the body and provide it with oxygen, but they also protect the body from harmful substances and carry these toxins to the kidneys so they can be disposed. The blood cells have a definite life cycle, just as all living organisms do. They live and die, flourish or deteriorate. A little more than half of blood is a straw-colored clear liquid call plasma. The liquid carries the cells and platelets which help to clot the blood. Without the platelets, you would bleed to death. When you lose a small amount of blood from an accident or injury, the platelets cause the blood to clot so the bleeding stops. Since new blood is always being made inside of your bones, the body can replace the lost blood. When the human body loses a lot of blood through a major wound, that blood has to be replaced or the body dies usually with a blood transfusion. Unfortunately, everybody’s blood is not the same. There are four different types and the blood also has factors which make it even more unique. So the blood received through a transfusion must match your own. Patients can donate their own blood ahead of time if they are having elective surgery, thus assuring them the blood is a perfect match. Otherwise, the patient must rely on the various tests done by blood banks that will assure the blood they receive from other people is a match. Platelets The human body does not handle excessive blood loss well. Therefore, the body has ways of protecting itself. If, for some reason, sudden blood loss occurs, the blood platelets kick into action. Platelets are irregularly-shaped, colorless bodies that are present in blood. Their sticky surface lets them, along with other substances, form clots to stop bleeding. When bleeding from a wound suddenly occurs, the platelets gather at the wound and attempt to block the blood flow. The mineral calcium, vitamin K, and a protein called fibrinogen help the platelets form a clot. A clot begins to form when the blood is exposed to air. The platelets sense the presence of air and begin to break apart. They react with the fibrinogen to begin forming fibrin, which resembles tiny threads. The fibrin threads then begin to form a web-like mesh that traps the blood cells within it. This mesh of blood cells hardens as it dries, forming a clot, or " scab. " Calcium and vitamin K must be present in blood to support the formation of clots. If your blood is lacking these nutrients, it will take longer than normal for your blood to clot. If these nutrients are missing, you could bleed to death. A healthy diet provides most people with enough vitamins and minerals, but vitamin supplements are sometimes needed. A scab is an external blood clot that we can easily see, but there are also internal blood clots. A bruise, or black-and-blue mark, is the result of a blood clot. Both scabs and bruises are clots that lead to healing. Some clots can be extremely dangerous. A blood clot that forms inside of a blood vessel can be deadly because it blocks the flow of blood, cutting off the supply of oxygen. A stroke is the result of a clot in an artery of the brain. Without a steady supply of oxygen, the brain cannot function normally. If the oxygen flow is broken, paralysis, brain damage, loss of sensory perceptions, or even death may occur. Plasma Plasma is a straw-colored, clear liquid that is 90 percent water, and is an essential ingredient for human survival. It might seem like plasma is less important than the blood cells it carries. But that would be like saying that the stream is less important than the fish that swims in it. You can't have one without the other. Besides water, plasma also contains dissolved salts and minerals like calcium, sodium, magnesium, and potassium. Microbe-fighting antibodies travel to the battlefields of disease by hitching a ride in the plasma. Without plasma, the life-giving blood cells would be left floundering without transportation. Never underestimate the importance of plasma. Blood Types In some ways, every person's blood is the same, but when you look at it closely, you can see the differences. It has been observed that two distinctive molecules are represented in blood cells. “A” type molecules, “B” type molecules, or a mixture of both are the significant factors in naming the blood type a person may have. If the red blood cells contain only “A” type molecules, then that blood is called type A. . If the red blood cell had only " B " molecules on it, that blood is called type B. If the red blood cell had a mixture of both molecules, that blood is called type “AB”. If the red blood cell had neither then the blood is called type “O”. Scientists found that if the types are mixed together, the blood cells begin to clump together in the blood vessels, causing a condition where a person may die. This is why it is so important that before a transfusion is made, that the blood types are matched. Type “O” blood can be given to anyone, but there is still a small risk involved. A person with type A blood can donate blood to a person with type A or type AB. A person with type B blood can donate blood to a person with type B or type AB. A person with type AB blood can donate blood to a person with type AB only. A person with type O blood can donate to anyone. A person with type A blood can receive blood from a person with type A or type O. A person with type B blood can receive blood from a person with type B or type O. A person with type AB blood can receive blood from anyone. A person with type O blood can receive blood from a person with type O only. Because of these patterns, a person with type O blood is said to be a universal donor. A person with type AB blood is said to be a universal receiver. In general, however, it is still best to mix blood of matching types and Rh factors. Rh Factor When scientists first began to study the make up of blood, they studied Rhesus monkeys because their blood is so similar to humans. During this study, a certain blood protein was discovered. This protein is also present in the blood of some people. Other people do not have the protein. If your blood has the protein, your blood is said to be Rh positive (Rh+). If your blood does not have the protein, your blood is said to be Rh negative (Rh-). If a person with negative blood gives blood to someone who has positive blood, the negative and positive cells fight each other. This causes a deadly situation. Red Blood Cells Red blood cells are extremely important part of the blood. A drop of blood contains millions of red blood cells. These cells are continuously traveling through your body delivering oxygen and removing waste. If they weren't, your body would slowly die. Red blood cells are red only because they contain a protein chemical called hemoglobin which is bright red in color. Hemoglobin contains the element Iron, making it an excellent vehicle for transporting oxygen and carbon dioxide. As blood passes through the lungs, oxygen molecules attach to the hemoglobin. As the blood passes through the body's tissue, the hemoglobin releases the oxygen to the cells. The empty hemoglobin molecules then bond with the tissue's carbon dioxide or other waste gases, transporting it away. Over time, the red blood cells get worn out and eventually die. The average life cycle of a red blood cell is 120 days. Your bones are continually producing new blood cells, replenishing your supply. The blood itself, however, is re-circulated throughout your body, not being remade all of the time. Since the human body is continually making more blood, it is safe for healthy adults to donate blood. The blood is then stored for use in emergency situations. Initially after giving blood, the donor may feel some momentary lightheadedness due to the loss of oxygen-rich red blood cells and blood sugar. The body quickly stabilizes itself. White Cells Whenever a germ or infection enters the body, the white blood cells become warriors and chase down the germ cells to kill them. The white blood cells are continually on the lookout for signs of disease. When a germ does appear, some the white blood cells will produce protective antibodies that will overpower the germ. Others will surround and eat the bacteria. The white blood cells have a rather short life cycle. A drop of blood can contain anywhere from 7 000 to 25 000 white blood cells at a time. If an invading infection fights back and persists, that number will significantly increase. A consistently high number of white blood cells is a symptom of Leukemia, a cancer of the blood. A Leukemia patient may have as many as 50 000 white blood cells in a single drop of blood. Info gathered from http://sln.fi.edu/biosci/blood/platelet.html Hugs, Deanna LUPUS Serenity Prayer... Lord, grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to hide the bodies of doctors I shot when they said, You're perfectly healthy, it's all in your head " Quote Link to comment Share on other sites More sharing options...
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