Chapter 19 The Cardiovascular System - The Blood PDF

Principles of Anatomy and Physiology 14th Edition CHAPTER 19 INTENDED LEARNING OUTCOMES 1. Know the functions of blood 2. Describe clearly the composition and volume of whole blood 3. Describe the composition of plasma and its properties 4. Know the different cell types making up the for...

Principles of Anatomy and Physiology 14th Edition CHAPTER 19 INTENDED LEARNING OUTCOMES 1. Know the functions of blood 2. Describe clearly the composition and volume of whole blood 3. Describe the composition of plasma and its properties 4. Know the different cell types making up the formed elements and its function of each type 5. Define briefly anemia, polycythemia, leukopenia, and leukocytosis and its causes 6. Explain effectively hemostasis, the general process of blood clotting and inhibition 7. Know the factors that may inhibit or enhance the blood clotting process 8. Describe the ABO and Rh blood groups 9. Discuss briefly the basis for a blood transfusion The Cardiovascular System: The Blood Cardiovascular System = blood + heart + blood vessels Hematology = study of blood, blood-forming tissues, & disorder Blood is a connective tissue that is composed of plasma and formed elements Functions and Properties of Blood Blood is a liquid connective tissue consisting of cells surrounded by a liquid matrix (plasma). Functions and Properties of Blood ▪ The cellular components (formed elements) of blood include red blood cells, white blood cells and platelets. ▪ The plasma portion of blood consists of water, proteins and other solutes.  Functions and Properties of Blood Components of blood Functions and Properties of Blood Functions and Properties of Blood ▪ Blood transports oxygen, carbon dioxide, nutrients, hormones, heat and waste products. ▪ Blood regulates homeostasis of all body fluids, pH, body temperature and water content of cells. ▪ Blood protects against excessive loss by clotting and against infections through the use of white blood cells.  Functions and Properties of Blood TBV (total blood volume) = 4-6 L or 8% of body weight * (males 5 - 6L; females 4 - 5 L) TBV is regulated by ADH (Antidiuretic Hormone) , Aldosterone and ANP (Atrial Natriuretic Peptide) ADH = regulates water content in the blood Aldosterone = helps the kidney hold unto salt & water ANP = decreases total blood volume to decrease blood pressure Functions and Properties of Blood Formation of Blood Cells ▪ Lymphocytes are able to live for years while most other blood cells live for hours, days, or weeks. ▪ The number of red blood cells and platelets remains rather steady while that of white blood cells varies depending on invading pathogens and other foreign antigens. ▪ The process of producing blood cells is hemopoiesis (hematopoiesis). Pluripotent stem cells differentiate into each of the different types of blood cells. Formation of Blood Cells Red Blood Cells ▪ Red blood cells (erythrocytes) contain the protein hemoglobin that is used to carry oxygen to all cells and to carry 23% of total carbon dioxide to the lungs. ▪ Each hemoglobin molecule contains an iron ion which allows each molecule to bind four oxygen molecules. ▪ Red blood cells have no nucleus or other organelles and are biconcave discs. The lack of a nucleus and the shape allow the cells to efficiently carry oxygen. Red Blood Cells Red Blood Cells ▪ Hemoglobin is also involved in regulating blood flow and blood pressure via the release of nitric oxide which causes vasodilation that improves blood flow and enhances oxygen delivery. ▪ Red blood cells also contain carbonic anhydrase which catalyzes the conversion of carbon dioxide and water to carbonic acid. This compound transports about 70% of carbon dioxide in the plasma. It is also a buffer. Red Blood Cells ▪ Red blood cells live for only about 120 days. Dead cells are removed from the circulation by the spleen and liver. ▪ Breakdown products from the cells are recycled and reused. Red Blood Cells ▪ Erythropoiesis (production of red blood cells) begins in the red bone marrow. Reticulocytes (immature red blood cells) enter the circulation and mature in 1 to 2 days. ▪ Erythropoietin, a hormone released by the kidneys in response to hypoxia (lowered oxygen concentration) stimulates differentiation of hematopoietic stem cells into erythrocytes. White Blood Cells ▪ White blood cells (leukocytes) contain a nucleus and organelles, but no hemoglobin. ▪ Leukocytes are classified as either granular (containing vesicles that appear when the cells are stained) or agranular (containing no granules). ▪ Granular leukocytes: neutrophils, eosinophils, basophils White Blood Cells White Blood Cells ▪ White blood cells may live for several months or years. Their main function is to combat invading microbes. ▪ During an invasion, many white blood cells are able to leave the bloodstream and collect at sites of invasion. The process is called emigration (diapedesis). White Blood Cells White Blood Cells ▪ In general, an elevation in the white blood count usually indicates an infection or inflammation. ▪ A low white blood cell count may develop due to several causes. ▪ A differential white blood cell count will help to determine if a problem exists. White Blood Cells Platelets ▪ Platelets are used to clot the blood. ▪ Under the influence of the hormone thrombopoietin, hemopoietic stem cells differentiate into platelets. ▪ Megakaryocytes in red bone marrow splinter into 2000–3000 fragments to create the platelets that contain many vesicles but no nucleus. ▪ Platelets survive for only 5 to 9 Platelets Platelets Stem Cell Transplants from Bone Marrow and Cord Blood ▪ Bone marrow transplants are performed to replace cancerous red bone marrow with normal red bone marrow. The donor’s marrow is usually collected from the iliac crest of the hip bone. ▪ Stem cells collected from an umbilical cord after birth are frozen and may also be used and have advantages over bone marrow transplants. Hemostasis Hemostasis means to stop bleeding. The process involves: ▪ Vascular spasm ▪ Platelet plug formation ▪ Blood clotting (coagulation)  Hemostasis Platelet Plug Formation PLT adhesion = PLT’s sticks to the damaged blood vessel wall * PLT release rxn * PLT’s become “spiny” * release their granules (clotthing chemicals) PLT aggregation = PLT’s stick to each other * PLT plug gets bigger & bigger * stops bleeding * PLT aggregation is inhibited by aspirin (vascular spasm also inhib. by aspirin)  Hemostasis Coagulation = Clot formation Liquid portion of unclotted blood is called plasma, liquid portion of clotted blood is called serum (no more coag. factors in it) Blood = cells+fibrin mesh made by coag. factors. 3 Stages *Formation of prothromninase (prothrombin activator) *Conversion of prothrombin into thrombin *Conversion of soluble fibrogen into insoluble fibrin Coag. Factors = 11 plasma proteins, plus Ca2+ * Clotting cascade can be initiated by either the extrinsic or intrinsic pathway *Extrinsic pathway - few steps and occurs rapidly - protein “tissue factor” (TF) leaks into the blood *Intrinsic pathway - more complex and more slower in response to damage to endothelial cells or phospholipid released to activated platelets *These coag. factors interact in a specific sequence, to eventually convert fibrinogen into fibrin strands *Each coag. factor has a name and a roman numeral *ex: coag. factor III = tissue factor; it is released from damaged cells Hemostasis ▪ Blood clotting involves several clotting (coagulation) factors identified by Roman numerals and divided into three stages. ▪ The three stages are the extrinsic pathway, intrinsic pathway and common pathway. Hemostasis Stages of clotting Hemostasis Hemostasis ▪ Once the clot forms, it consolidates (tightens) to pull the edges of the damaged vessel together. ▪ Vitamin K is needed for normal clot formation although it is not directly involved. It is used in the synthesis of 4 clotting factors. ▪ Small, unwanted clots are usually dissolved by plasmin (fibrinolysin). Blood Groups and Blood Types ▪ Blood is characterized into different blood groups based on the presence or absence of glycoprotein and glycolipid antigens (agglutinogens) on the surface of red blood cells. ▪ There are 24 blood groups and more than 100 antigens ▪ Because these antigens are genetically controlled, blood types vary among different populations. ▪ Classification is based on antigens labeled A, B or AB with O being the absence of the antigens. ▪ An additional antigen, Rh, is present in 85% of humans. Blood Groups and Blood Types Blood Groups and Blood Types Blood plasma usually contains antibodies (agglutinins) that react with A or B antigens. An individual will not have agglutinins against his or her own blood type. Blood Groups and Blood Types 1. RBC’s contain surface proteins called blood group Ag’s (generally determined) 2. The plasma contains Ab’s (agglutinins or isoantigens) directed against blood group Ag’s which are MISSING from that person’s own RBC’s Blood Groups and Blood Types Blood Groups and Blood Types ▪ In order to determine a person’s blood type, typing and cross- matching are performed. ▪ A drop of blood is mixed with an antiserum that will agglutinate blood cells that possess agglutinogens that react with it. Blood Groups and Blood Types Hemolytic Disease of the Newborn ▪ At birth, small amounts of fetal blood leak into the maternal circulation. If the baby is Rh+ and the mother is Rh–, she will develop antibodies to the Rh factor. ▪ During her next pregnancy with an Rh+ baby, when she transfers antibodies to the fetus (a normal occurrence), transferred anti Rh antibodies will attack some of the fetus’ red blood cells causing Hemolytic Disease of the Newborn Hemolytic Disease of the Newborn (HDN) If mother is Rh (-) and baby is Rh (+), mother may produce Ab’s against the baby’s Rh-Ag First baby is usually NOT affected; second and future Rh(+) babies may be affected HDN can cause hemolysis of baby’s RBCs, jaundice, mental retardation, death of baby HDN can be prevented by administering Rh Immunoglobulin (RhoGam/RhIg) to the Rh(-) mother within 72 hours after delivering each Rh(+) baby (RhoGam = anti-Rh Ab’s from a donor). RhIg is also given as a preventive measure around the 28th week of pregnancy Disorders: Homeostatic Imbalances ▪ Sickle cell disease is a genetic anemia (oxygen-carrying capacity of the blood is reduced). ▪ The red blood cells of individuals with this disease contain hemoglobin-S (Hb-S) that causes red blood cells to bend into a sickle shape when it gives up oxygen to the interstitial fluid.  Disorders: Homeostatic Imbalances Anemia - oxygen-carrying capacity of the blood is reduced - RBC count or hgb deficiency. *Iron-deficiency, pernicious, hemorrhagic, hemolytic, thalassemia, and aplastic Sickle cell disease-inherited disorder due to abnormal kind of hgb - RBCs are sickle shaped Hemophilia - inherited deficiency of clotting - bledding disorder Acute leukemia - malignant disease - uncontrolled production and accumulation of mature leukocytes Chronic leukemia - accumulation of mature leukocytes in the bloodstream Thrombocytopenia - decreased level of platelets ( clotting ability) Pancytopenia - level of all blood cells ASSIGNMENT 1. Draw the cells on pages 81–82 and provide their functions. 2. Cut and staple the pages, then submit them to your class representative. 3. The class representative should arrange them alphabetically and submit them to me by 11/18/2024 (Monday). THANK YOU AND HAVE A NICE DAY