Blood Journey > Creation of Blood What Is Blood Made Of? Blood is a mixture of cells and watery liquid, called plasma, that the cells float in. It also contains other things like nutrients (such as sugar), hormones, clotting agents, and waste products to be flushed out of the body. There are three kinds of cells in the blood: red blood cells, white blood cells, and platelets. Red blood cells carry oxygen from the lungs throughout the body, white blood cells help fight infection, and platelets help in clotting. Red blood cells (also called erythrocytes) are the most numerous, making up 40-45 percent of one's blood, and they give blood its characteristic color. Red blood cells are shaped like tiny doughnuts, with an indentation in the center instead of a hole. They contain a special molecule called hemoglobin, which carries the oxygen. In the lungs, where there is a lot of oxygen, the hemoglobin molecules loosely bind with oxygen. Each molecule of hemoglobin contains four iron atoms, and each iron atom can bind with one molecule of oxygen, allowing each hemoglobin molecule to carry four molecules of oxygen. In the capillaries, where there is little oxygen, the hemoglobin readily sheds the oxygen it is carrying and allows it to be absorbed by the body's cells. The iron in hemoglobin is what makes blood red. White blood cells (leukocytes) are the body's mobile warriors in the battle against infection and invasion. There are three types of white blood cell: granulocytes, lymphocytes, and monocytes. There are, in turn, three kinds of granulocyte: neutrophils, eosinophils, and basophils. (Granulocytes are called that because they contain granules that hold digestive enzymes.) Neutrophils kill invading bacteria by ingesting and then digesting them. Eosinophils kill parasites, and are involved in allergic reactions. Basophils also function in allergic reactions, but are not well understood. lymphocyte: T cells and B lymphocytes. T cells direct the activity of the immune system. B lymphocytes produce antibodies, which destroy foreign bodies. Monocytes, the largest kind of white blood cells, enter the tissues of the body and turn into even larger cells called macrophages. These eat foreign bacteria and destroy damaged, old, and dead cells of the body itself. The blood cells called platelets (thrombocytes) help blood to clot, in several different ways. When bleeding occurs, platelets clump together to help form a clot. Also, when they are exposed to air (as they would be by a wound), platelets start breaking down and release a substance into the bloodstream. This substance starts a chain of chemical events that eventually causes a protein in the blood, fibrinogen, to turn into a different substance, fibrin, which forms long threads. These threads tangle up red blood cells to help form a clot, or scab, over the wound. In their "resting" state, platelets look like two plates stuck together (hence the name). When "activated" and helping to form a clot, they change shape and look like tiny roundish blobs with tentacles. At only two to three microns, they are the smallest kind of blood cell. Plasma is a clear, straw-colored liquid that carries the blood cells and various hormones, nutrients, and so on through the body. It makes up a little more than half of the total blood volume. Plasma is about 90 percent water. Much of the other ten percent comprises various kinds of protein molecules, including enzymes, clotting agents, immunoglobulins (part of the immune system), and proteins that carry hormones, vitamins, cholesterol, and other things the body needs. Plasma also contains sugar (glucose) and electrolytes like sodium, potassium, and calcium, as well as other things like the aforementioned hormones, vitamins, and cholesterol. -- Sue Wilson 2002 Educational Broadcasting Corporation http://www.pbs.org/wnet/redgold/journey/phas e1_a1.html (January 11, 2010) Lymphocytes are key parts of the body's immune system. There are two kinds of
Plasma Blood consists of a liquid (55% by volume) and solid particles (45%), including several types of cells (also called "corpuscles" in older books). The liquid is called plasma. This is mainly water, but it has many things dissolved in it. These substances are either needed by cells of the body, or surplus to their requirements, but tissue fluid derived from blood either brings or takes them away, in solution. It also protects all the body's cells from damage due to osmosis. White Cells There are not so many white cells as red cells; they are in fact about 600 times fewer. However they can leave the blood system and move towards micro-organisms (mostly bacteria and viruses) which are causing infections in any part of the body. There are several types of white cells, but they all share the function of fighting diseases, and we make use of them in vaccination to give us immunity against diseases. Source: http://media-2.web.britannica.com/ebmedia/71/91871-034-da6ba042.jpg Types of white cells: a phagocyte, and its function is to engulf and destroy invading microorganisms. a lymphocyte, and its function is to produce antibodies against invading microorganisms. Platelets These are not actually cells, but parts of cells; they have a role in starting the clotting of blood when a blood vessel is damaged. (see section below) This is usually a natural defence reaction when the body is wounded in some way, leading to a clot at the exposed surface of the body, which hardens into a scab, under which the process of healing may take place. In other circumstances, however, a similar reaction may also occur, producing a circulating clot called a "thrombosis" which may be lifethreatening in its own right if it blocks an important blood vessel inside the body (see later). This is the cause of heart attacks and strokes (prevention of blood flow in part of brain or heart). Some of these may be due to our lifestyle, including diet and stress. For example, in "hardening of the arteries", blood vessels are partly blocked by the buildup of cholesterol. Source:http://www.aplasticanemiaindia.co.in/images/Blood %20components.jpg
Team Roles: Reader Reporter Understanding Parts of the Blood Recorder Reviewer Research Topic: You will be responsible for sharing information on your research topic with the rest of the class. Together, we will create a base of information you will need to complete your model. Use the space below to take notes and plan your contributions. Things to think about: colour, shape, size, function, name, proportional composition (% of the total) 3 Points to Share with the Class: 1. 2. 3.
Creating A Model Using the supplies in the room and the information collected from the other research teams, your team has 15 minutes to create a model of 2 litres of blood. You should refer to the information we have collected together on the four main components of healthy blood. Use the rubric below as an important step in your planning! Component White Blood Cells Red Blood Cells Plasma Platelets Scientific Inquiry Overall Appearance Group Cooperation Criteria Appropriate material chosen that helps explain their function in the blood. They appear in the correct proportion in the model. Appropriate material chosen that helps explain their function in the blood. They appear in the correct proportion in the model. Appropriate material chosen that helps explain their function in the blood. It appears in the correct proportion in the model. Appropriate material chosen that helps explain their function in the blood. They appear in the correct proportion in the model. Taking proper steps to draft, design and create the model. Taking proper care of the materials and supplies. Ensuring work area is safe and clean. The subject matter is treated with respect. The model is presented in a clean, well-cared for manner. Materials used are in good shape. Each group member is respected and is encouraged to contribute. Assistance is given to other groups who request or need it. Group Evaluation 0 (lowest) 3 (highest) The most all penetrating spirit before which will open the possibility of tilting not tables, but planets, is the spirit of free human inquiry. Believe only in that. Dmitri Mendeleev
Reader Read aloud all instructions to your group. Read aloud all articles/written reference material. Read aloud the final product written product to the group before the Reporter presents it. Recorder Ensure all portions of handouts have each group member s name As the group is discussing your blood component, write down important facts and details. After/as the group is agreeing, write down the three crucial points you will share with the class. Reviewer Ensure everyone understands all instructions before moving ahead. Help the group on task and keep an eye on the time- don t run out of it! Before the group presents, review the instructions and ensure you have completed all directions to the best of your abilities. Reporter Serve as a mediator in the group if there is disagreement. Build consensus (help everyone participate and come to a decision everyone respects). Report your group s discussion and three crucial points and model to the class. Reader Read aloud all instructions to your group. Read aloud all articles/written reference material. Read aloud the final product written product to the group before the Reporter presents it. Recorder Ensure all portions of handouts have each group member s name. As the group is discussing your blood component, write down important facts and details. After/as the group is agreeing, write down the three crucial points you will share with the class. Reviewer Ensure everyone understands all instructions before moving ahead. Help the group on task and keep an eye on the time- don t run out of it! Before the group presents, review the instructions and ensure you have completed all directions to the best of your abilities. Reporter Serve as a mediator in the group if there is disagreement. Build consensus (help everyone participate and come to a decision everyone respects). Report your group s discussion and three crucial points and model to the class.
White Blood Cells Red Blood Cells
Platelets Plasma