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19 Cards in this Set
- Front
- Back
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% of blood
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25%
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shape
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bi concave disc
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layers (3)
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glycocalyx
lipid bilayer membrane skeleton |
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features of glycocalyx
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made of glycolipids and glycoproteins
change shape as cell ages - leading to phagocytosis in spleen, liver, bone marrow |
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size
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6.2 -8.2µm long
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approx no. of molecules of Hb per RBC
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300 million
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hormone responsible for regulation
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erythropoietin (EPO)
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erythropoietin
function... secreted by... |
stimulates MATURATION of RBCs
90% from kidneys, remainder mostly by liver |
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production of RBCs increased by...
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functional ability of RBCs to transport oxygen, NOT number of RBCs
any condition that reduces quantity of oxygen delivered to the tissues normally increases RBC production |
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EPO mechanism
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important for final maturation of RBC (essential for synthesis of DNA)
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Vit B12 (cyanocobalamin)
folic acid |
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pernicious anaemia caused by...
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maturation failure caused by poor absorption of Vit B12 from GI tract
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Hb molecule
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structure of RBC
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2x alpha chains
2x beta chains heme group in each chain |
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O2 combination with RBC
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O2 combines loosely and reversibly with one of the coordination bonds, NOT the positive bonds on the iron (Fe2+)
O2 does not become ionic, but is carried, and released as molecular O2 |
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RBCs destroyed by...
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phagocytosis by macrophages in liver (Kupfer cells), spleen and bone marrow
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intracellularly RBCs have no...
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nucleus
mitochondria ER |
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intracellularly RBCs have...
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enzymes
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intracellular RBC enzymes...(5)
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metabolise and produce ATP
maintain pliability of cell membrane maintain membrane transport of ions keep the iron in the ferris form (rather than ferric which cannot carry O2) prevent oxidation of proteins in RBC |
