which is essential for allowing CO 2 and H 2 0 to reactbuffer system more later

Which is essential for allowing co 2 and h 2 0 to

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., which is essential for allowing CO 2 and H 2 0 to react.(buffer system more later) Hemoglobin - consists of four protein chains attached to a heme (iron containing) group. One oxygen atom can bind to each heme group therefore making the hemoglobin completely saturated. Carbon monoxide binds irreversibly to hemoglobin, thus rendering it ineffective to carry oxygen. Fetal hemoglobin is much more effective at binding oxygen than is adult hemoglobin. Iron is necessary for hemoglobin to function, properly and without it anemia can ensue. Main component of RBC B. Formation of RBC’s 1. General Information Hematopoiesis takes place in the red bone marrow. Marrow makes about an ounce of blood each day. Hemocytoblast – stem cells for blood cell production. 2. Erythropoiesis – formation of RBC’s Hemocytoblast myeloid stem cell proerythroblast early erythroblast late erythroblast normoblast reticulocyte erythrocyte. o Hemocytoblast: bone marrow stem cell, can become any blood cell o Proerythroblast: RBC stem cell, has receptors for EPO o Erythroblast: begins making hemoglobin o Reticulocyte: often found in hypoxic situations Hemoglobin begins accumulating in the second phase Nucleus is ejected form the normoblast. RBC’s are produced at a rate of about 2 million/sec! 3. Hormonal Controls 3
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Nur 0013 Spring 2014 Erythropoietin (EPO) – hormone released by kidney cells in response to: Decreased RBC in circulation Decreased O 2 availability Increased tissue demands for O2 EPO stimulates red bone marrow to produce more RBC’s Within 1-2 days reticulocyte count increases. Hypoxia is a major factor in stimulating this system C. Death of RBC - Hemolysis After 90-120 days membrane becomes fragile and rigid Membrane degraded in either spleen or liver Hemoglobin disposed by liver. Broken into heme and globin components Heme broken down into bilirubin in SI, and iron is recycled. Globins – are recycled D. RBC disorders. Are often related to not enough or too many cells Anemias – Lack of RBC’s- blood loss, malformation Hemorrhagic Hemolytic (Ecoli) 4
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Nur 0013 Spring 2014 Aplastic(bone marrow destroyed) Low Hemoglobin counts Iron Deficient Pernicious(lack of intrinsic factor and hence vit B12) Defective Hemoglobin – Often genetic Thalassemias – faulty globin chains Sickle cell, single amino acid change during transcription Causes the cell to become stiff and elongated due to malformed hemoglobin One of the more common genetic diseases that affects RBC Polycythemias Polycythemia vera – often caused by marrow cancer. Blood doping – secondary cause IV. Formed Elements - WBC A. Leukocytes (WBC) ~5000-10,000/µL Are truly cells , they are only about 1% of blood by volume. Hormones and other stressors can stimulate their production in red bone marrow (known as leukopoeisis). Stimulants for formation can be hormonal or other stressors Once produced they move out of the blood vessels in a process known as diapedesis and eventually to the site of an immune response.
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