Chapter 17: Blood

William Harvey Discovered the nature of blood and circulation with the heart.

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.1: The major components of whole blood, p Plasma (55% of whole blood) Erythrocytes (45% of whole blood) Buffy coat: leukocytes and platelets (<1% of whole blood) Formed elements Centrifuge Withdraw blood and place in tube 2 1

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.2: Photomicrograph of a human blood smear stained with Wright’s stain, p Erythrocytes LymphocyteNeutrophils PlateletsMonocyte

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.9: Types and relative percentages of leukocytes in normal blood, p Formed elements Platelets Leukocytes Erythrocytes Differential WBC count (All total 4800– 10,800/ml) Granulocytes Neutrophils (50–70%) Agranulocytes Lymphocytes (25–45%) Eosinophils (2–4%) Basophils (0.5–1%) Monocytes (3–8%)

John Jacob Abel 1857 – 1938 Endocrinologist who was extensively involved with work on insulin and adrenalin. His most famous work however was in designing blood dialysis.

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.4: Structure of hemoglobin, p (a) (b) N N CH 2 CH 2 COOH CH 3 H3CH3C H3CH3C H 2 C=CH N N Fe Polypeptide chain 22 11 11 22 Hemoglobin Iron-containing heme group

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.6: Erythropoietin mechanism for regulating erythropoiesis, p Homeostasis: Normal blood oxygen levels Increases O 2 - carrying ability of blood Erythropoietin stimulates red bone marrow Reduces O 2 levels in blood Kidney (and liver to a smaller extent) releases erythropoietin Enhanced erythropoiesis increases RBC count Stimulus: Hypoxia due to decreased RBC count, decreased amount of hemoglobin, or decreased availability of O 2 Start Imbalance

Higher Elevation leads to lowered oxygen levels.

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.7: Life cycle of red blood cells, p Hemoglobin Amino acids Globin Raw materials are made available in blood for erythrocyte synthesis. Iron is bound to transferrin and released to blood from liver as needed for erythropoiesis Food nutrients, including amino acids, Fe, B 12, and folic acid are absorbed from intestine and enter blood Heme Circulation Iron stored as ferritin, hemosiderin Bilirubin Bilirubin is picked up from blood by liver, secreted into intestine in bile, metabolized to stercobilin by bacteria and excreted in feces Erythropoietin levels rise in blood. Erythropoietin and necessary raw materials in blood promote erythropoiesis in red bone marrow. New erythrocytes enter bloodstream; function about 120 days. Low O 2 levels in blood stimulate kidneys to produce erythropoietin. Aged and damaged red blood cells are engulfed by macrophages of liver, spleen, and bone marrow; the hemoglobin is broken down

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.5: Erythropoiesis: genesis of red blood cells, p Stem cell HemocytoblastProerythroblast Early erythroblast Late erythroblast Normoblast Phase 1 Ribosome synthesis Phase 2 Hemoglobin accumulation Phase 3 Ejection of nucleus ReticulocyteErythrocyte Committed cellDevelopmental pathway

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.11: Leukocyte formation, p Hemocytoblast Myeloid stem cell Lymphoid stem cell Myeloblast Lymphoblast Stem cells Committed cells Promyelocyte PromonocyteProlymphocyte Eosinophilic myelocyte Neutrophilic myelocyte Basophilic myelocyte Eosinophilic band cells Neutrophilic band cells Basophilic band cells Develop- mental pathway EosinophilsNeutrophilsBasophils Granular leukocytes Plasma cells Some become Monocytes Lymphocytes Macrophages (tissues) Agranular leukocytes Some become (a)(b)(c)(d)(e)

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.12: Genesis of platelets, p Stem cellDevelopmental pathway HemocytoblastMegakaryoblastPromegakaryocyteMegakaryocytePlatelets

Karl Landsteiner – 1901 discovered the ABO blood groups

Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Figure 17.15: Blood typing of ABO blood types, p Serum Anti-A RBCs Anti-B Type AB (contains agglutinogens A and B) Blood being tested Type B (contains agglutinogen B) Type A (contains agglutinogen A) Type O (contains no agglutinogens)