Why do we have blood? Where does it come from? Norelle, Olympia, Wash
Dear Norelle, Our bodies have many living parts, like skin, muscle, brain and bones. Blood helps keep these parts alive and healthy. The system that moves our blood around the body is sort of like a citys postal service, said my friend. Suchy-Dicey is a scientist at who is really curious about blood. Her research helps people at risk for diseases. She said it first helps to know blood is actually made up of different things: red blood cells, white blood cells, platelets, and plasma. If you think of your circulatory system like the postal service, mail carriers are the red blood cells. They transport important packages and letters (oxygen) over a vast network of streets and highways (blood vessels). About a gallon and a half of blood circulates through the human body, dropping off these deliveries, 24 hours a day. The strong heart muscle pumps blood out into the body. ItPworksPhard, too. The force needed to squeeze a tennis ball is similar to what you need to squeeze blood out of the heart. White blood cells help your body infections. There are lots of different types of white blood cells with different jobs. Some of them fight off tiny bacteria and fungi. Some of them fight off viruses or other invaders. All of the white blood cells jobs have one common mission: keeping you healthy. Platelets help to keep you healthy. Whenever you get a cut or scrape, it is these disc-shaped parts come to the rescue.
Platelets help stop blood from flowing,Pprevent you from losing blood, and keep out invaders. Plasma is a watery solution with a few other things floating in it, like salt and proteins. It flows, carrying other cells freely along those streets and highways we know as blood vessels. Now for the second part of your question. PSuchy-Dicey said the body produces blood cells in your bones. Specifically, they are produced in the soft fatty part inside your bones called bone marrow. Your plasma is formed mostly using water you drink. Thats why its really important to drink enough water each day, Suchy-Dicey adds. While on the issue of water, heres a quick activity you can try to find out about how much blood your heart pumps in a minute. Youll need a bucket of water, an empty bucket, and a small Dixie cup. Fill a bucket with about a gallon of water. Have a friend set a timer for one minute and see how many little cups of water you can move to the empty bucket. Each time your heart beats it moves about a small Dixie cups worth of blood. It takes our heart about one minute to pump about a gallon of blood. Can you move the liquid faster than a heart? Try it out sometime and let me know how it works. Sincerely, Dr. Universe ABOUTPASK DR. UNIVERSE Ask Dr. UniverseP connects K-8 students with researchers at Washington State University through Q A. Students can submit science questions on theP Ppage. Are you a teacher, parent, or curious grown-up?
P Follow alongPonP PorP Do you want to reprint this Q A? PJust send a message to Dr. Universe@wsu. edu. is 55% and about 45% different types of blood. The blood plasma is a light yellow liquid. Over 90% of blood plasma is water, while less than 10% is dissolved substances, mostly. Blood plasma also contains, and such as and. Over 99% of the solid particles present in blood are cells that are called ( ) due to their red color. The rest are pale or colorless ( ) and ( ). look like with indentations on top and on the bottom. They can bend easily to Бsqueeze throughБ narrow. Red blood cells have no, in contrast to many other cells. Each contains, which can transport. In tiny blood vessels in the lung the red blood cells pick up oxygen from inhaled air and carry it through the bloodstream to all parts of the body. When they reach their goal, they release it again. The cells need oxygen for, which also creates as a waste product. The red blood cells then pick up the carbon dioxide and transport it back to the lung. There we exhale it when we breathe out. can also pick up or release hydrogen and nitrogen. When picking up or releasing hydrogen they help to keep the pH level of the blood steady; by releasing nitrogen the expand, and. Red blood cells have a life cycle of about 120 days. When they are too old or damaged they are broken down in the, or. ( ) have a and do not contain. There are different types of white blood cells.
They are classified according to how their nucleus is shaped and what the inside of the cell looks like under a microscope. have small granules in their. and also contain granules, but these granules are extremely small and cannot be seen under a microscope. There are many more red than white blood cells in the blood. play an important role in the. Here the different blood cells have different functions: some fight intruders such as, or themselves and render them harmless. Others produce, which specifically target foreign objects or like viruses. also have a part in : they make sure, for instance, that someone with a house dust gets a when he or she comes into contact with dust. Certain can also kill cancerous cells that have been produced elsewhere in the body. Most of the white blood cells have a lifespan of only a few hours to several days. Some lymphocytes can remain in the body for many years, though. ( ) also look like little, as do the, and they also have no. However, they are much smaller than the red blood cells. They play an important role in : if a is damaged Б for instance when you are cut by a knife Б the healing process begins with blood platelets binding closely together on the inside of the damaged wall of the blood vessel. This causes a plug to form quickly that closes the temporarily: thrombocytes usually live only 5 to 9 days. Old thrombocytes are mainly disposed of in the.