BIOL 2002C 1st Edition Lecture 4 Outline of Last Lecture I Exam and Start of Blood Outline of Current Lecture I Hematopoiesis II Hemoglobin III RBC abnormalities IV White Blood Cells Current Lecture 7 What is pluripotent hematopoietic stem cell it can give rise to any blood cell a Erythropoiesis RBC formation Hematopoietic stem cell myelod stem cells proerythroblast early erythroblast intermediate erythroblast late erythroblasts extrudes nucleus reticulocyte erythrocyte b Leukopoiesis WBC formation myeloid stem cells Myeloblasts accumulate lysosomes progranulocytes myelocytes granules develop nuclear shape forms band cells eosinophils neutrophils basophils live hours to days lymphoid stem cells Lymphoblast prolymphocyte in lymph lymphocytes live days to lifetime lymphoid stem cells Monoblasts promonocytes in lymph monocytes live several months c Thrombopoiesis Platelet Formation Myeloid stem cells Megakaryoblasts undergo mitosis many times without These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute cytokinesis produce a megakaryocyte breaks up into platelets Describe the overall structure of erythrocytes 8 Biconcave discs increase surface area to help diffuse oxygen and carbon dioxide through Contractile proteins help RBC s contract to fit through capillaries actin and tropomyosin No nucleus they are anucleate 9 Describe the structure and function of hemoglobin Fig 19 4 Heme 4 Heme s iron containing Globin 4 globin 2 alpha 2 beta it s a polypeptide chain Relate which gases associate with hemoglobin and how Define Oxyhemoglobin the iron in each heme binds reversibly with one oxygen Deoxyhemoglobin no oxygen is bound Carbaminohemoglobin blood carbon dioxide combine with amino acids of globin occurs more readily in deoxyhemoglobin Carboxyhemoglobin occurs when carbon monoxide binds to hemoglobin 10 Compare fetal and adult hemoglobin as to structure and affinity for oxygen as well as to sickle cells 11 Embryonic and fetal hemoglobin has a high affinity for O 2 than adult hemoglobin Each hemoglobin can bind 4 O2 Adult has 2 alpha and 2 beta but fetal has 2 alpha and 2 gamma Mutation on beta globin on chromosome 11 creates sickle cell anemia the sickle shape is in the deoxygenated form Discuss the life history of red blood cells including production and hemoglobin breakdown Fig 19 5 Know erythropoietin and the organs involved Produced in red bone marrow from hematopoietic stem cells Locations in fetus and young child everywhere Locations in adults epiphysis of long bones pelvis ribs sternum vertebrae proximal femur and humerus The developmental pathway consists of three phases Phase 1 Ribosome synthesis in early erythroblasts Phase 2 Hemoglobin accumulation in late erythroblasts Phase 3 ejection of the nucleus from late erythroblasts and formation of reticulocytes 12 Increased production when O2 levels are low Causes of low O2 levels which would increase erythropoietin secretion include Being a smoker High altitude anemia Hemoglobin breakdown 13 Erythropoietin hormone that binds to steam cells to commit it to being a RBC the kidney and liver as a backup if the kidney is damaged produces it Average life span of an RBC is 120 days Dead RBC s destroyed in the spleen and liver by macrophages RBC s hemoglobin is broken down to heme globin Then Iron Fe of heme put into protein iron complexes stored in the liver and spleen transported by protein transferrin returned to the bone marrow for re use Heme broken down to bilirubin bound to albumin and transported in blood to liver then becomes part of bile and is excreted by the liver into small intestine Bacteria in intestines metabolize bilirubin and resulting pigments give feces their brown color Globin is broken down into amino acids Define the following RBC abnormalities Polycythemia too many red blood cells blood is more viscous and moves slower Anemia Iron deficiency iron deficient or folate deficiency Pernicious vitamin B12 common in elderly Aplastic destruction inhibition of hemopoietic parts of red bone marrow Sickle cell disease recessive carrying both genes homozygous has the disease Sickle cell trait heterozygous for the trait carrying the trait Thalassemia deficient globin chain 14 Compare the structures and functions of the five types of white blood cells List the WBC s in order from most to least common Table 19 2 and Fig 19 8 Granulocytes large granules in cytoplasm stain with the Wright stain a all are phagocytes b multi lobed nuclei polymophonuclear c basophils neutrophils eosinophil Agranulocytes granules in stain not shown a Nucleus not lobes b Lymphocytes monocytes