Anatomy and Physiology, Seventh Edition Rod R. Seeley Idaho State University Trent D. Stephens Idaho State University Philip Tate Phoenix College Chapter 19 Lecture Outline* *See PowerPoint Image Slides for all figures and tables pre-inserted into PowerPoint without notes. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Cardiovascular System Chapter 19 Cardiovascular System Blood

Functions of Blood Transport of gases, nutrients and waste products; e.g. oxygen Transport of processed molecules; e.g., precursor of vitamin D from skin to liver then kidneys Transport of regulatory molecules; e.g., hormones Regulation of pH and osmosis (normal pH of most body tissues between 7.35 and 7.45) Maintenance of body temperature; e.g., warm blood shunted to the interior of the body Protection against foreign substances; e.g., antibodies Clot formation

Plasma Liquid part of blood. Colloid: liquid containing suspended substances that don’t settle out of solution 91% water. Remainder proteins, ions, nutrients, waste products, gases, regulatory substances Proteins: Albumins: viscosity, osmotic pressure, buffer, transports fatty acids, free bilirubin, thyroid hormones Globulins: Transports lipids, carbohydrates, hormones, ions, antibodies, and complement Fibrinogen: blood clotting

Plasma, cont. Ions: involved in osmosis, membrane potentials, and acid-base balance Nutrients: glucose, amino acids, triacylglycerol, cholesterol, vitamins Waste Products: Urea, uric acid, creatinine, ammonia salts. Breakdown products of protein metabolism Bilirubin. Breakdown product of RBCs Lactic acid. End product of anaerobic respiration Gases: oxygen, carbon dioxide, and inert nitrogen Regulatory substances: hormones, enzymes

Composition of Blood

Formed Elements Red blood cells (erythrocytes). Biconcave discs, anucleate, contain hemoglobin; transports oxygen and carbon dioxide. White blood cells (leukocytes) Granulocytes: cytoplasm contains large granules; have multi-lobed nuclei. Three distinctive types: neutrophils, eosinophils, basophils Agranulocytes: cytoplasm contains small granules and nuclei that are not lobed. Two distinctive types: lymphocytes and monocytes Platelets (thrombocytes). Cell fragment. Form platelet plugs, release chemicals necessary for blood clotting.

Production of Formed Elements Hematopoiesis or hemopoiesis: Process of blood cell production Stem cells: All formed elements derived from single population Proerythroblasts: Develop into red blood cells Myeloblasts: Develop into basophils, neutrophils, eosinophils Lymphoblasts: Develop into lymphocytes Monoblasts: Develop into monocytes Megakaryoblasts: Develop into platelets

Hematopoiesis

Red Blood Cells Found in higher concentration in male than in female plasma Components 1/3 Hemoglobin 2/3 Lipids, ATP, carbonic anhydrase

RBC Function: Transport Oxygen from lungs to tissues: 98.5% attached to hemoglobin; 1.5% dissolved in plasma Carbon dioxide from tissues to lungs. 7% dissolved in plasma 23% in combination with hemoglobin 70% transported as bicarbonate ions produced as a result of combination of H2O and CO2 because of enzyme carbonic anhydrase found within RBCs

Hemoglobin Types of hemoglobin Embryonic and fetal: have greater attraction for oxygen than adult. Fetal production stops after birth. Adult Oxyhemoglobin: transporting oxygen Dexoyhemoglobin Carbaminohemoglobin: transporting carbon dioxide

Hemoglobin Composition Four globin molecules (polypeptide chains): Transport carbon dioxide (carbonic anhydrase involved), nitric oxide. NO brought from lungs to tissues, induces smooth muscles to relax, lowering BP. Four heme molecules, each containing one iron atom: transport oxygen Iron required for oxygen transport. Iron absorbed in upper small intestine; absorption increased by stomach acid and vitamin C. Iron lost in urine, feces, menstrual fluid.

Erythropoiesis RBCs last 120 days in circulation (enucleated) Production of red blood cells Stem cells → proerythroblasts → early erythroblasts → intermediate erythroblasts → late erythroblasts → reticulocytes Erythropoietin: hormone stimulates RBC production; produced by kidneys in response to low blood O2 levels.

Hemoglobin Breakdown Insert Process Fig. 19.6 with verbiage; Animation Hemoglobin Breakdown.exe and

White Blood Cells Protect body against microorganisms and remove dead cells and debris Movements Ameboid: pseudopods Diapedesis: cells become thin, elongate and move either between or through endothelial cells of capillaries Chemotaxis: attraction to and movement toward foreign materials or damaged cells. Accumulation of dead white cells and bacteria is pus.

Neutrophils: after leaving bone marrow, stay in circulation 10-12 hours then move into other tissues. Become motile, phagocytize bacteria, antigen-antibody complexes and other foreign matter. Secrete lysozyme. Last 1-2 days. Eosinophils. Leave circulation and enter tissues during inflammatory response. Prevalent in allergic reactions. Destroy inflammatory chemicals like histamine. Release chemicals that help destroy tapeworms, flukes, pinworms, and hookworms.

Basophils: least common Basophils: least common. Leave circulation and migrate through tissues, play a role in both inflammatory response and allergic reactions. Produce histamine and heparin. Lymphocytes: produced in red bone marrow but then migrate to lymphatic tissues and proliferate. Responsible for antibody production. Studied extensively with the immune system. Monocytes: remain in circulation for 3 days, leave circulation and become macrophages. Phagocytic cells. Can break down antigens and present them to lymphocytes for recognition.

Platelets Cell fragments pinched off from megakaryocytes in red bone marrow Surface glycoproteins and proteins allow adhesion to other molecules; i.e., collagen Important in preventing blood loss Platelet plugs Promoting formation and contraction of clots

Hemostasis Arrest of bleeding Events preventing excessive blood loss Vascular spasm: Vasoconstriction of damaged blood vessels. Can occlude small vessels. Caused by thromboxanes from platelets and endothelin from damaged endothelial cells. Platelet plug formation Coagulation or blood clotting

Platelet Plug Formation Platelet adhesion. Occurs when von Willebrand factor connects collagen and platelets. Platelet release reaction. The release of ADP, thromboxanes, and other chemicals that activate other platelets. They in turn undergo the release reaction: cascade effect. Platelet aggregation. Activated platelets express surface receptors that bind fibrinogen (protein found in plasma). Fibrinogen forms a bridge between platelets: platelet plug. Expression of coagulation factor V and phospholipids. Important for coagulation

Coagulation Stages Activation of prothrombinase Conversion of prothrombin to thrombin Conversion of fibrinogen to fibrin Coagulation factors. Proteins found in plasma. Circulate in inactive state until tissues are injured. Damaged tissues and platelets produce chemicals that begin activation of the factors. Pathways Extrinsic Intrinsic Result: blood clot. A network of threadlike fibrin fibers, trapped blood cells, platelets and fluid Coagulation

Clot Formation

Extrinsic Clotting Pathway Begins with chemicals outside of blood Stage 1 Damaged tissues release tissue factor (TF; factor III) When Ca2+ is present, forms complex with factor VII, activating factor X Prothrombinase is formed Stage 2: prothrombinase converts prothrombin into thrombin Stage 3 Thrombin converts fibrinogen to fibrin Thrombin activates factor XIII, which stabilizes clot

Intrinsic Clotting Pathway Begins with chemicals that are part of the blood Stage 1 In damaged blood vessels, factor XII comes in contact with exposed collagen, activating factor XII Stimulates factor XI, activates factor IX Activated factor IX joins with factor VIII, platelet phospholipids and Ca2+ to activate factor X Prothrombinase is formed Stages 2 and 3 progress to clot formation

Control of Clot Formation Anticoagulants: prevent coagulation factors from initiating clot formation. Coagulation occurs when coagulation factor concentration exceeds a given threshold. At site of injury, threshold is exceeded. Anticoagulants Antithrombin: produced by liver, slowly inactivates thrombin Heparin: produced by basophils and endothelial cells. Increases effectiveness of antithrombin Prostacyclin: prostaglandin derivate from endothelial cells. Causes vasodilation and inhibits release of coagulating factors from platelets

Fibrinolysis Clot retraction. Fibrin threads of clot attached to blood vessel walls. Platelets produce processes that attach to fibrin threads. Actin and myosin molecules within platelets contract, pulling edges of wound together and squeezing out serum. Clot dissolved by activity of plasmin, an enzyme which hydrolyzes fibrin

Blood Grouping Transfusion: transfer of blood or blood components from one individual to another Infusion: introduction of fluid other than blood Determined by antigens (agglutinogens) on surface of RBCs Antibodies (agglutinins) can bind to RBC antigens, resulting in agglutination (clumping) or hemolysis (rupture) of RBCs Groups: ABO and Rh

ABO Blood Groups

Agglutination Reaction

Transfusion Type A blood has anti-B antibodies; Type B blood has anti-A antibodies Suggested that these antibodies are present because of exposure to A and B antigens on bacteria and food Donor: gives blood. Recipient: receives blood Type O as “universal donor”. Can actually cause transfusion reactions because of antibodies in O blood plasma

Rh Blood Group First studied in rhesus monkeys Types Rh positive: Have these antigens present on surface of RBCs Rh negative: Do not have these antigens present Hemolytic disease of the newborn (HDN) Rh positive fetus, Rh negative mother. Late in pregnancy, Rh antigens of fetus cross placenta (through a tear in placenta or during delivery); mother creates antiRh antibodies (primary response) Second Rh positive pregnancy might initiate secondary response and HDN (potentially fatal to fetus since antibodies to its RBCs would cross the placenta from the mother to the fetus, destroying fetal RBCs). Injection of RhoGAM. Contains antibodies against Rh antigens. Antibodies attach to any fetal RBCs and they are destroyed.

Erythroblastosis Fetalis

Diagnostic Blood Tests Type and Crossmatch: determination of ABO and Rh blood types. Red cells tested against antibodies Complete Blood Count Red Blood Count: number of RBCs/ microliter of blood Hemoglobin Measurement: grams of hemoglobin/100 mL of blood. For a male, 14-18, female 12-16 g/100 mL Hematocrit Measurement: percent of blood that is RBCs White Blood Cell Count: 5,000-10,000 /microliter of blood

Hematocrit

Differential White Blood Count: determines percentage of each of the five types of WBC Neutrophils: 60-70% Lymphocytes: 20-30% Monocytes: 2-8% Eosinophils: 1-4% Basophils: 0.5-1% Clotting Platelet Count: 250,000- 400,000/microliter Prothrombin Time Measurement: measures how long it takes for blood to start clotting. 9-12 seconds. To test, thromboplastin is added to whole plasma Blood Chemistry: composition of materials dissolved or suspended in the plasma. Used to assess functioning of many body systems