Lifeblood Lab Activity

Transcription

1 History of Blood: It is the universal symbol of horror, of death, yet it is the one thing that keeps you living. It is the blood that is coursing through your veins. But, what do you really know about your blood? Why is its function so vital? And why is your blood an irreplaceable commodity? Blood, which appears to us as a flowing red liquid, is amazingly complex. It has two basic components plasma and solids that are carried in the plasma. Plasma is 91.5 % water. It also contains hundreds of chemicals, such as hormones, sugar, salts, cholesterol, proteins and minerals. The prime functions of blood are as follows: (1) The red cells in the blood which give the blood its color are keys to respiration. The oxygen from the lungs travels to the 60 trillion cells of the body via these red blood cells. On the return trip to the lungs, the blood cells carry carbon dioxide, the by-products of the cells energy production. (2) White blood cells can move about the body to wherever there is a need. They serve as the policemen of the body by invading and fighting any foreign bacteria that could harm the body. Passing through the capillary walls, the white blood cells have powerful enzymes that eat offending bacteria. Pus that forms at the site of an infection is an indication that the white blood cells have been busy. Pus is primarily made of white blood cells and dead bacteria. (3) Lymphocytes are a type of white blood cell that enhances your immunity to infection and bacteria. (4) Platelets in the blood attach themselves to cuts or abrasions to plug up the wound and stop the bleeding. (5) Plasma carries our digested food to the cells in our body to be utilized as energy. It delivers carbohydrates, proteins, fats, minerals, salts and vitamins to the areas where they can do the most good. On it s return, the plasma carries waste products urea and uric acid to the kidneys. (6) If the body is too hot, the capillaries near the skin open and the blood carries excess heat to the surface. When it is cold, the blood stays deeper inside the body and so conserves body heat. The blood, then, helps to regulate our body temperature at 98.6 degrees Fahrenheit. As we all know, there are various blood types. So far 15 different types of blood have been identified. If transfused blood is not of the right type, a person may die. Yet, as

2 science is discovering, blood type is not the only unique factor to be considered. The unique combination of anti-bodies, hormones, proteins make it impossible to match correctly. There is, in fact, a realization that our blood may be just as unique as our fingerprint. From this brief glimpse, we can see just how amazing our blood really is. All of which should give us a renewed respect for this amazing gift we have all received our body. Where are blood cells made? Blood cells are made in the bone marrow. The bone marrow is the spongy material in the center of the bones that produces about 95 percent of the body's blood cells. There are other organs and systems in our bodies that help regulate blood cells. The lymph nodes, spleen, and liver help regulate the production, destruction, and differentiation (developing a specific function) of cells. The production and development of new cells is a process called hematopoiesis. Blood cells formed in the bone marrow start out as a stem cell. A "stem cell" (or hematopoietic cell) is the initial phase of all blood cells. As the stem cell matures, several distinct cells evolve such as the red blood cells, white blood cells, and platelets. Immature blood cells are also called blasts. Some blasts stay in the marrow to mature and others travel to other parts of the body to develop into mature, functioning blood cells.

3 What are the functions of blood cells? The primary function of red blood cells, or erythrocytes, is to carry oxygen and carbon dioxide. Hemoglobin (Hgb) is an important protein in the red blood cells that carries oxygen from the lungs to all parts of our body. The primary function of white blood cells, or leukocytes, is to fight infection. There are several types of white blood cells and each has its own role in fighting bacterial, viral, fungal, and parasitic infections. Types of white blood cells that are most important for helping protect the body from infection and foreign cells include the following: Granulocytes eosinophils basophils neutrophils Lymphoid cells monocytes lymphocytes White blood cells: Help heal wounds not only by fighting infection but also by ingesting matter such as dead cells, tissue debris, and old red blood cells. Protect us from foreign bodies that enter the blood stream, such as allergens. Protect against mutated cells, such as cancer. The primary function of platelets, or thrombocytes, is blood clotting. Platelets are much smaller in size than the other blood cells. They group together to form clumps, or a plug, in the hole of a vessel to stop bleeding. What is a complete blood cell count (CBC)? A complete blood cell count is a measurement of size, number, and maturity of the different blood cells in a specific volume of blood. A complete blood cell count can be used to determine many abnormalities with either the production or destruction of blood cells. Variations from the normal number, size, or maturity of the blood cells can be used to indicate an infection or disease process. Often with an infection, the number of white blood cells will be elevated. Many forms of cancer can affect the bone marrow production of blood cells. An increase in the immature white blood cells in a complete blood cell count can be associated with leukemia. Anemia and sickle cell disease will have abnormally low hemoglobin.

4 Common hematological tests: Some common hematological tests include the following: Test Complete blood count (CBC), which includes: white blood cell count (WBC) red blood cell count (RBC) platelet count hematocrit red blood cell volume (HCT) hemoglobin concentration (HB)-the oxygen-carrying pigment in red blood cells differential blood count Uses To aid in diagnosing anemia, certain cancers of the blood, and to monitor blood loss and infection. Platelet count To diagnose and/or to monitor bleeding and clotting disorders. Prothrombin time (PT) To evaluate bleeding and clotting disorders and to monitor anticoagulation (anti-clotting) therapies. Procedure: The following websites may be helpful during your activity: For each blood cell shown in the subsequent diagrams please describe the cell s function(s), appearance, size, and abundance. For appearance describe the relative shape of the cell and the nucleus, if one is present. Also, describe the color of the cell, the color of the cell contents, and the color of the cell s nucleus.

5 Erythrocytes (Red blood cells) Red blood cells perform the most important blood duty. A single drop of blood contains millions of red blood cells, which are constantly 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 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.

6 Shape of cell: Size: Abundance: Color of cell: Color of cellular contents: Function: Unique features: Leukocytes (White blood cells) The leukocytes, or white blood cells, defend the body against infecting organisms and foreign agents, both in the tissues and in the bloodstream itself. Human blood contains about 5,000 to 10,000 leukocytes per cubic millimeter; the number increases in the presence of infection. An extraordinary and prolonged proliferation of leukocytes is known as leukemia. This overproduction suppresses the production of normal blood cells. Conversely, a sharp decrease in the number of leukocytes strips the blood of its defense against infection and is an equally serious condition. A dramatic fall in levels of certain white blood cells occurs in persons with. Leukocytes as well as erythrocytes are formed from stem cells in the bone marrow. They have nuclei and are classified into two groups: granulocytes and agranulocytes. The granulocytes form in the bone marrow and account for about 70% of all white blood cells. Granulocytes include three types of cells: neutrophils, eosinophils, and basophils. Neutrophils constitute the vast majority of granulocytes. They travel about by ameboid movement and can surround and destroy bacteria and other foreign particles. The eosinophils, ordinarily about 2% of the granulocyte count, increase in number in the presence of allergic disorders and parasitic infestations. The basophils account for about 1% of the granulocytes. They release chemicals such as histamine and play a role in the inflammatory response to infection. The agranulocytes include the monocytes and the lymphocytes. Monocytes are derived from the phagocytic cells that line many vascular and lymph channels, called the reticuloendothelial system. Monocytes ordinarily number 4% to 8% of the white cells. They move to areas of infection, where they are transformed into macrophages, large

7 phagocytic cells that trap and destroy organisms left behind by the granulocytes and lymphocytes. In certain diseases of long duration (tuberculosis, malaria, and typhoid) the monocytes act as the main instrument of defense. Lymphocytes, under normal conditions, make up about 20 to 35% of all white cells, but proliferate rapidly in the face of infection. There are two basic types of lymphocytes: the B-lymphocytes and the T lymphocytes. B-lymphocytes tend to migrate into the connective tissue, where they develop into plasma cells that produce highly specific antibodies against foreign antigens. Other B-lymphocytes act as memory cells, ready for subsequent infection by the same organism. Some T lymphocytes kill invading cells directly; others interact with other immune system cells, regulating the immune response. Neutrophils Size: Color of cell: Abundance: Function: Color of cellular granules: Color of nucleus: Unique features: Shape of nucleus:

8 Eosinophils Shape of cell: Size: Color of cell: Color of cellular granules: Color of nucleus: Shape of nucleus: Abundance: Function: Unique features:

9 Basophils Shape of cell: Size: Color of cell: Color of cellular granules: Color of nucleus: Shape of nucleus: Abundance: Function: Unique features:

10 Lymphocyte Shape of cell: Size: Color of cell: Shape of nucleus: Abundance: Function: Color of cellular granules: Color of nucleus: Unique features: Monocytes

11 Shape of cell: Size: Color of cell: Color of cellular granules: Color of nucleus: Shape of nucleus: Abundance: Function: Unique features: Questions: 1. What are the two (2) major functions of blood? 2. List the components of blood. 3. How do thrombocytes function in our bloodstream? 4. Describe plasma. 5. Describe where and how the body makes blood cells. 6. Describe the functioning of an erythrocyte. 7. List and describe the function of each type of granulocyte.

12 8. How do lymphocytes and monocytes function? 9. Describe a complete blood count (CBC) and its uses. 10. Compare granulocytes with lymphocytes or agranulocytes. 11. How do granulocytes move? 12. Describe how monocytes act as macrophages. 13. List the two (2) types of lymphocytes. 14. Describe how B-lymphocytes function as plasma cells. 15. Describe the function of T-lymphocytes.