Chapter 18 Blood 10 22 2013 Hematology o Hematology is the study of blood o Main functions of the circulatory system include o Transportation of nutrients hormones oxygen and carbon dioxide o Protection from infection white blood cells o Controls our fluid balance between our blood and tissues acid and base balance and body temperature o Blood is made up of plasma the fluid portion plus the formed elements o Formed elements include red blood cells erythrocytes white blood cells leukocytes and platelets Plasma o Made up of water proteins nutrients electrolytes wastes hormones gases clotting factors o Hormones dissolve in plasma o Plasma without the clotting factors serum o Proteins in blood are important for transportation of solutes blood clotting and defense against foreign material o Albumin most abundant plasma protein buffers pH transport solutes o Plasma contains nitrogenous wastes that are a normal byproduct of cellular metabolism transported to kidneys for removal o Main electrolyte in blood is sodium o Where sodium goes water follows o The more water more blood volume o More blood volume more blood pressure Blood o Blood is about 5x more viscous than water o The higher the viscosity the slower it flows o Main contributor to blood viscosity is red blood cells o Changes in viscosity can affect the rate of blood flow and put strain on the heart o Blood doping o Ejecting erythropoietin to make more red blood cells o More red blood cells becomes thicker and your heart has to work harder o More red blood cells mean more oxygen o Blood osmolarity is determined by the dissolved solutes determines flow o Without enough solutes in blood fluid would be filtered into tissues but of fluid not reabsorbed o With too many solutes the opposite Blood production o Hemopoiesis occurs in red bone marry o All blood cells arise from a common hemopoietic stem cell Red Blood Cells RBCs Erythrocytes o Carries oxygen and carbon dioxide CO2 o Not involved in immune system or blood clotting o Shaped round and flat with a sunken in center o Maximizes the surface area o Lack all organelles ejecting them towards the end of their development anaerobic o Don t use oxygen to make energy o Plasma membrane contains cytoskeletal proteins which give the cells o Hemoglobin Hb red pigment that gives blood its color binds to oxygen strength and flexibility and carbon dioxide o In tertiary structure oxygen o Made up of four proteins called globins two alpha chains and two beta chains with one heme group attached to each globin o Each heme group has an iron ion at the center and one molecule of o Each Hb carries 4 oxygen molecules o Carbon dioxide binds to the globin chains o Hematocrit percentage of blood made up of red blood cells o More androgens for testosterone o Males 42 52 o Females 37 48 o Menstruation o Inversely proportional to body fat percentage o Erythropoiesis formation of RBCs o Takes 3 5 days o Erythropoietin EPO hormone secreted primarily from the kidneys stimulates RBC production in red blood cells o Greater amounts of EPO can be released in response to blood loss or hypoxemia not enough oxygen in the blood o Hypoxemia can be due to blood loss increases in consumption or atmosphere changes o RBCs survive only 120 days because they have no repair system o Most die in the spleen which constantly filters and cleans blood o Hemolysis rupture of RBCs releasing hemoglobin o Divided into heme and globin o Globin is hydrolyzed into tree amino acids which can be used as building blocks for other proteins o Iron is stored and reused o Heme is converted to bilirubin o Bilirubin is released with bile into small intestine during digestion bacteria in large intestine convert to urobiliogen which has a brown color and urochrome which is yellow o Polycythemia too many red blood cells o Due to tumor dehydration or hypoxemia o Results in increased blood volume increased viscosity o Anemia too little red blood cells o Due to low erythropoiesis low Hb production hemorrhage or excessive hemolysis o May also occur as a result of kidney failure o Sickle cell disease hemoglobin molecules are shaped weirdly Blood Types o On the surface of red blood cells are proteins glycoproteins and glycolipids called antigens or agglutinogens o The body recognizes these antigens and the immune system will not attack our own RBCs with these antigens o If our immune system comes in contact with RBCs with different antigens white blood cells will release proteisn called antibodies which will bind to the foreign antigens causing the RBCs to blump agglutinate and be removed o Type A has type A antigens on surface of RBCs o Has anti B antibodies in plasma o Can accept type A or type O o Will agglutinate type AB or B o Type B has type B antigens on surface of RBCs o Has anti A antibodies in plasma o Can accept type A or type O o Will agglutinate type AB or type A o Type AB has type A antigens AND type B antigens on surface of RBCs o Has NO antibodies in plasma o Can accept type A type B type AB type O o Universal recipient o Type O has NO type A or type B antigens on surface of RBCs o Has BOTH anti A and anti B antibodies o Can accept type O o Will agglutinate type A B and AB o Universal Donor Rh Factor o Rh is another group determines if blood type is positive or negative o Most common is antigen D so if an individual has one or two copies of the gene for this antigen they are positive o More common for positive than negative o Anti D antibodies are not in the blood but form in Rh individuals exposed to Rh blood o Takes time for antibodies to form White Blood Cells WBCs Leukocytes o White blood cells are the least abundant type of formed element but necessary to protect us as part of the immune system o Less than 1 o Spend little time in circulation o Settle in tissues or stays in bone marrow o Retain organelles abundant rough ER ribosomes Golgi lysosomes o Lots of lysosomes o Named based on what dye they take up and presence of granules o Granulocytes neutrophils eosinophils basophils o Agranulocytes lymphocytes monocytes o Neurtrophils granules contain lysozyme enzyme and antibiotics primarily fight of bacteria o Eosinophils fight off large pathogens such as tapeworms by surrounding it and releasing digestive enzymes smaller than parasites they fight off abundant in respiratory digestive and urinary tracts o Basophils assist other WBCs by releasing histamine vasodilator and heparin an anticoagulant Help get more WBC to the area o