ch. 18 Blood

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Functions of the Circulatory System
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Terms in this set (47)
Seven kinds of formed elements/ Components and General Properties of Blood 2
1)Erythrocytes: red blood cells (RBCs)
Cell fragments from special cell in bone marrow
Leukocytes: white blood cells (WBCs)
Five leukocyte types divided into two categories

Granulocytes (with granules)

Agranulocytes (without granules)
Hematocrit—centrifuge blood to separate componentsErythrocytes (Red Blood Cells)are heaviest and settle first 37% to 52% total volumeWhite blood cells and platelets1% total volume Buffy coatPlasmaThe remainder of volume 47% to 63% Complex mixture of water, proteins, nutrients, electrolytes, nitrogenous wastes, hormones, and gasesComponents of bloodblood plasma-Plasma -Three major categories of plasma proteins -Plasma proteins are formed by liver -Nitrogenous compounds -Nutrients -Dissolved , , and nitrogen -ElectrolytesPlasma—liquid portion of blood -Serumserum: remaining fluid when blood clots and solids are removed Identical to plasma except for the absence of fibrinogenThree major categories of plasma proteins-Albumin -Globulin -FibrinogenAlbumins: smallest and most abundant Contribute to viscosity and osmolarity; influence blood pressure, flow, and fluid balanceGlobulins (antibodies)(antibodies) Provide immune system functions Alpha, beta, and gamma globulinsFibrinogenPrecursor of fibrin threads that help form blood clotsPlasma proteins are formed by liverExcept globulins (produced by plasma cells)nitrogenous compoundsFree amino acids from dietary protein or tissue breakdown Nitrogenous wastes (urea)Nitrogenous wastes (urea)Toxic end products of catabolism Normally removed by the kidneysNutrientsGlucose, vitamins, fats, cholesterol, phospholipids, and mineralsElectrolytesmakes up 90% of plasma cationsViscosity of blood—resistance of a fluid to flow, resulting from the cohesion of its particles -Whole blood -Plasmawhole blood4.5 to 5.5 times as viscous as waterPlasmais 2.0 times as viscous as water Important in circulatory functionosmolarity of blood—the total molarity of those dissolved particles that cannot pass through the blood vessel wall >If too high, blood absorbs too much water, increasing the blood pressure >If too low, too much water stays in tissue, blood pressure drops, and edema occurs >Optimum osmolarity is achieved by the body's regulation of sodium ions, proteins, and red blood cellsStarvation and Plasma Protein Deficiency-Hypoproteinemia -KwashiorkorhypoproteinemiaDeficiency of plasma proteins Extreme starvation Liver or kidney disease Severe burnsKwashiorkorChildren with severe protein deficiency Fed on cereals once weaned Thin arms and legs Swollen abdomenHow Blood is Produced 1-Adult production of 400 billion platelets, 100-200 billion RBCs, and 10 billion WBCs every day -Hemopoiesis -Hemopoietic tissues produce blood cellsHemopoiesis—production of blood, especially its formed elementsHemopoietic tissues produce blood cells-Yolk sac produces stem cells for first blood cells >Colonize fetal bone marrow, liver, spleen, and thymus -Liver stops producing blood cells at birth -Spleen remains involved with lymphocyte production -Red bone marrow produces all seven formed elementsRed bone marrow produces all seven formed elements -Pluripotent stem cells (PPSC) -Colony -Myeloid hemopoiesis -Lymphoid hemopoiesispluripotent stem cells (PPSC)Formerly called hemocytoblasts or hemopoietic stem cellscolony-forming unit—specialized stem cells only producing one class of formed element of bloodmyeloid hemopoiesis—blood formation in the bone marrowlymphoid hemopoiesis—blood formation in the lymphatic organs (beyond infancy this only involves lymphocytes)Expected Learning OutcomesDiscuss the structure and function of erythrocytes (RBCs). Describe the structure and function of hemoglobin. State and define some clinical measurements of RBC and hemoglobin quantities. Describe the life cycle of erythrocytes. Name and describe the types, causes, and effects of RBC excesses and deficiencies.Erythrocytes-Two principal functions 1.Carry oxygen from lungs to cell tissues 2.Pick up from tissues and bring to lungs -Insufficient RBCs can cause death in minutes due to lack of oxygen to tissues -Disc-shaped cell with thick rim 7.5 μm diameter and 2.0 μm thick at rim -Lose nearly all organelles during development -Lack mitochondria -Anaerobic fermentation to produce ATP -Lack of nucleus and DNA No protein synthesis or mitosisstructure of erythrocytesBiconcave, anucleateForm and Function of erythrocyte-Blood type determined by surface glycoproteins and glycolipids -Gas transport -Cytoskeletal proteins (spectrin and actin) give membrane durability and resilience Stretch and bend as squeezed through small capillaries Carbonic anhydrase (CAH) in cytoplasmCarbonic anhydrase (CAH) in cytoplasmProduces carbonic acid from and water Important role in gas transport and pH balance