Blood Functions Delivers oxygen and nutrients Transports metabolic wastes most sig waste is carbon dioxide and nitrogen Transports hormones Maintains body temperature Maintains body pH Maintains fluid volume kidneys will either absorb or release water but if absorbed it must go somewhere so blood maintains balance Prevents blood loss clotting proteins Prevents infection antibodies in plasma and complement proteins and white blood cells Components Formed Elements cellular components Erythrocytes RBC responsible for carrying respiratory gases highly modified to carry oxygen also carry CO2 45 of the total vol of blood is RBC dead cells during maturation the nucleus and other cellular organelles are lost and in place of those it accepts hemoglobin Components Formed Elements Erythrocytes Leukocytes white blood cells living 5 different types function in immune system cellular structure like RBC Components Formed Elements Erythrocytes Leukocytes Platelets cellular fragments also called thrombocytes main function is blood clotting short survival time all formed elements are formed in bone marrow all division takes place there Components Formed Elements Erythrocytes Leukocytes Platelets Plasma about 55 of blood Know this chart Erythrocytes Small Biconcave Anucleate no nucleus Contain the pigment hemoglobin which is modified for carrying Oxygen Contain antioxidant enzymes which attack free radicals Hemoglobin Globin protein bound to heme pigment heme pigment makes blood red 4 polypetide chains Globin quarternary structure 2 alphas 2 betas Heme Contains oxygen binding iron Hemoglobin Oxi vs Deoxyhemoglobin Carbaminohemoglobin Erythropoiesis formation of RBC Hemocytoblast pluripotent cell can give rise to many diff types of cells produces myeloid stem cell Myeloid stem cell becomes proerythroblast Proerythroblast becomes early erythroblast Early erythroblast becomes late erythroblast Late erythroblast becomes normoblast Normoblast loses organelles and nucleus and accumulates hemoglobin to become reticulocyte Reticulocytes mature in bloodstream to become erythrocytes Regulation of Erythropoiesis Erythropoietin hormone produced in kidney when oxygen levels of blood are low so its not when we lose cells that production is started but its when oxygen is low Testosterone stimulates kidneys to release erythropoietin another reason women have less RBC Iron absorbed in food we eat in intestines Stored in cells as ferritin and hemosiderin Transported in blood as transferrin B vitamins affect RBC production esp B12 and folic acid Dietary nutrients proteins lipids and carbs Erythrocyte Longevity Old erythrocytes destroyed by macrophages phagocystic cells Heme is split from globin occurs primarily in spleen Iron bound to proteins and stored Bilirubin is produced basically heme minus iron Picked up by liver and secreted as bile into intestine Pigment degraded and expelled in feces breakdown of RBC gives feces brown color Globin broken down to amino acids Erythrocyte Disorders Anemias low numbers of RBC 2 types low numbers or abnormal formed RBC Polycythemia too many RBC so it gets sludgy too thick so it doesn t circulate well Diapedesis Greek Dia through Pedan leak Leukocytes Complete cells with nuclei and organelles Display positive chemotaxis white blood cells attracted toward foreign cells Neutrophil Eosinophil Monocyte Basophil Lymphocyte Leukocytes Granulocytes Neutrophils majority of WBC 50 70 phagocytic cells function in inflammatory response function in destroying bacteria Eosinophils rare 2 4 attack parasitic wormsl Basophils rarest 1 produce histomine which is basodilater helps attract other WBC Agranulocytes Lymphocytes 25 of WBC large nucleus that makes up most of cell resides mostly in lymphatic system system that cleanses blood function in immunity T lymphocytes attack things like tumors B lymphocytes attack free floating foreign cells Monocytes largest unique U shaped nucleus name changes to macrophage when it moves out into bloodstream Leukopoiesis Hemocytoblasts give rise to myeloid stem cells and lymphoid stem cells Granulocyte Leukopoiesis Myeloid stem cells become myeloblasts committed cells Myeloblasts accumulate lysosomes to become promyelocytes Promyelocytes differentiate into myelocytes Cell division stops and nuclei arch to form band cells Nuclei constrict and segment to become mature granulocytes Agranulocyte Leukopoiesis Myeloid stem cells become monoblasts Monoblasts become promonocytes Promonocytes leave bone marrow and become monocytes in lymph tissues Agranulocyte Leukopoiesis Lymphoid stem cells become lymphoblasts Lymphoblasts become prolymphocytes Prolymphocytes leave bone marrow and become lymphocytes in lymph tissue Regulation of Leukopoiesis Interleukins Colony stimulating factors Leukocyte Disorders Leukemia cancerous condition of WBC Infectious mononucleosis increase in number of agranulocytes Leukopenia decreases in WBC counts immunocomprimised Platelets Anucleated cytoplasmic fragments of megakaryocytes Granules contain clotting chemicals Thrombopoiesis Hemocytoblasts give rise to myeloid stem cells Myeloid stems cells become megakaryoblasts committed cell Megakaryoblasts undergo repeated mitosis but no cytokinesis to form megakaryocytes Cytoplasmic extensions of megakaryocyes break off to be platelets Regulation of Thrombopoiesis Thrombopoietin hormone which stimulates platelet production Hemostasis blood clotting cessation of bleeding Vascular spasm constriction of blood vessel Platelet plug formation accumulation or agglutination of blood vessels at opening Coagulation blood must gel and clot protein associated with this is fibrin protein that forms a web like thing to gel blood Platelet Plug Formation Damage to blood vessel exposes underlying collagen fibers which cause release of 2 chemicals Also releases von Willebrand factor protein and thromboxane A2 prostiglandin Causes platelets to collect and adhere at site of damage Once attached thrombin what really causes clot to happen activates platelets to breakdown and release chemical contents Limitations to Platelet Plug Intact endothelial cells secrete PGI2 prostacyclin inhibits platelets from adhering and heparin prevent accumulation of platelets and blood cells from adhering Vitamin E quinone Intrinsic Pathway to Coagulation Series of reactions in which clotting factors converted to active forms Ultimately aggregated platelets platelet plug release PF3 PF3 activates other intermediate proteins leading to