The Composition of Blood and RBCs Blood is
The Composition of Blood and RBC’s Blood is a fluid connective tissue consisting of a matrix called plasma and several formed elements. Plasma contains dissolved proteins and is slightly denser than water. Formed elements include red and white blood cells and platelets. Red blood cells (aka erythrocytes) transport oxygen and carbon dioxide and make up 99% of all formed elements. White blood cells (aka leukocytes) function as part of the immune system. Platelets are small, membranous packets of cytoplasm that contain enzymes and allow the blood to clot. An adult male has about 5 -6 liters (female 4 -5 liters) of blood in their cardiovascular system. The temperature of blood is slightly above body temp. (100⁰F) and its p. H is slightly alkaline (7. 4)
Red blood cells (RBCs) contain the pigment hemoglobin, which binds and transports oxygen and carbon dioxide. A single drop of whole blood contains approximately 260 million RBCs. The shape of a single RBC is that of a biconcave disc with a thin central region. This shape serves 2 purposes: to give RBCs a large surface area to volume ration which increases diffusion, and allows RBCs to bend and flex to fit through narrow capillaries. RBC’s lose most of their organelles and thusly have no repair mechanisms. As a result they have a short life span, about 120 days. New RBCs are formed in the red bone marrow of the bones of the torso. Approximately 3 million new RBCs enter the circulation each second.
Antigens are (mostly) proteins that trigger an immune response. The membranes of all cells in your body contain surface antigens, which keep your immune system from attacking. The presence or absence of 3 antigens on the surface of RBCs (A, B or Rh) determines your blood type. Type A has antigen A only and thusly cannot receive Type B or AB blood. Type B has antigen B only. Type AB has both A and B and Type O has neither A nor B. The Rh antigen gives blood types the + or – portion. An Rh+ antigen can accept both + and – blood, but Rh- antigen can only receive – blood. Type O- blood is considered the universal donor blood type and Type AB+ blood is considered the universal recipient blood type.
1 st Left Side Activity Answer the following questions in complete sentences 1. What is the other name for red blood cells? For white blood cells? 2. What is the main function of red blood cells? Of white blood cells? Of platelets? 3. How many liters of blood does the average male have? The average female? 4. What pigment binds and transports oxygen and carbon dioxide? 5. How many RBCs enter circulation each second? How many in a drop of blood? 6. Why is the life span of RBCs so short? 7. Where are new RBCs formed? Name at least 4 skeletal bones where they are formed 8. What type of antigens do Type AB and Type O blood contain? 9. What type of blood could be given in transfusion to a Type A- person? 10. What type of blood could be given in transfusion to a Type AB+ person? 11. What type of blood do medical professionals always want when you are donating blood? 12. What type of blood types do you and your family have? (Ask your parents, if they don’t know write that my parents do not know)
2 nd Left Side Activity Create a Top Down Flow Chart with the word Blood at the top and the 4 components of blood in boxes or circles below it. Then extend out another step and give at least 2 facts about that component. Blood • Contains small proteins • Slightly denser than water Plasma 3 rd Left Side Activity Create a chart (example at right) stating each blood type and what blood types that blood can receive. You will need to figure this out from the last part of lecture and the example I have given you for Type A at right. . Blood Type Can receive these Blood Types A+ A+, A-, O+, O- A- A-, O- B+ BO+ 0 AB+ AB-
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