Week 1,2 The Blood(2) PDF - Cardiovascular System

Summary

This document is a set of lecture notes on the cardiovascular system, focusing on blood. It discusses blood composition, its functions, and the different components involved, including plasma proteins, formed elements, and blood clotting. It also details the different blood groups (ABO and Rh) and the production of blood cells. The notes include illustrations and diagrams to explain the concepts.

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Because learning changes everything.® Chapter 19 Cardiovascular System BLOOD Seeley’s ANATOMY & PHYSIOLOGY Thirteenth Edition Cinnamon VanPutte, Jennifer Regan, Andrew Russo © 2023 McGraw Hill, LLC....

Because learning changes everything.® Chapter 19 Cardiovascular System BLOOD Seeley’s ANATOMY & PHYSIOLOGY Thirteenth Edition Cinnamon VanPutte, Jennifer Regan, Andrew Russo © 2023 McGraw Hill, LLC. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill, LLC. Lecture Outline Blood is a fluid connective tissue composed of plasma, extracellular matrix, and formed elements, the cells of the tissue. Access the text alternative for slide images. © McGraw Hill, LLC 2 19.1 Functions of Blood Transport of gases, nutrients and waste products; for example. oxygen. Transport of processed molecules; for example, precursor of vitamin D from skin to liver then kidneys. Transport of regulatory molecules; for example, hormones. Regulation of pH and osmosis; buffers in blood help maintain normal pH (7.35-7.45). Maintenance of body temperature; for example, warm blood shunted to the exterior of the body and released as heat. Protection against foreign substances; for example, antibodies protect against microorganisms. Clot formation as the first step in tissue repair to stop blood loss. © McGraw Hill, LLC 3 19.2 Composition of Blood Blood: connective tissue with liquid matrix containing cells and cell fragments. Plasma is the liquid matrix. 55% of blood volume. Formed elements are the cells and cell fragments. 45% of blood volume. Total blood volume in females average = 4 to 5 L; males average = 5 to 6 L. © McGraw Hill, LLC 4 Composition of Blood liquidlibrary/Jupiter Images/Getty Images Access the text alternative for slide images. © McGraw Hill, LLC 5 19.3 Plasma Liquid matrix of blood. Plasma is a colloid: liquid containing suspended substances that don’t settle out of solution (mostly plasma proteins). 91% water. Remainder proteins, ions, nutrients, waste products, gases, regulatory substances. Composition remains relatively constant through various homeostatic mechanisms even though materials are constantly moving into and out of the blood. © McGraw Hill, LLC 6 Plasma Proteins Albumins: viscosity, osmotic pressure, buffer, transports fatty acids, bilirubin, thyroid hormones. (58% of proteins) Globulins: transports many substances, involved in immunity; α, β, γ types.(38% of proteins) Fibrinogen: blood clotting; serum is plasma without clotting factors. (4% of proteins) © McGraw Hill, LLC 7 Composition of Plasma 1 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. © McGraw Hill, LLC 8 19.4 Formed Elements Red blood cells (erythrocytes). 95% of the volume of formed elements. 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. © McGraw Hill, LLC 9 Formed Elements (a) National Cancer Institute/Science Photo Library/Science Source © McGraw Hill, LLC 10 Formed Elements of the Blood 1 TABLE 19.2 Formed Elements of the Blood Cell Type Illustration Description Function Abundance (cells/μL)* Red Blood Cell Biconcave disc; no nucleus; Transports O2 and CO2 4.2–5.4 million contains hemoglobin, which (females) A red blood cell has the shape of a flat disk or doughnut, which is round with an indentation in the center but is not hollow. colors the cell red; 7.5 μm in 4.7–6.1 million diameter (males) White Blood Spherical cells with a nucleus Five types of white blood 4500–11,000 Cells cells, each with specific functions Granulocytes Neutrophil Nucleus with two to five lobes Phagocytizes 55–70% of WBC connected by thin filaments; microorganisms and Neutrophil is the smallest of all granulocytes with a characteristic multi-lobed nucleus with 3-5 lobes joined by slender strand of genetic material. cytoplasmic granules stain a other substances light pink or reddish-purple; 10–12 μm in diameter Eosinophil Nucleus often bilobed; Attacks certain worm 1–4% of WBC cytoplasmic granules stain parasites; releases orange-red or bright red; 11– chemicals that modulate 14 μm in diameter inflammation; negatively An eosinophil has a nucleus with two lobes (bilobed) and a cytoplasm filled with approximately 200 large granules. impacts airways during asthma attacks © McGraw Hill, LLC 11 Formed Elements of the Blood 2 TABLE 19.2 Formed Elements of the Blood Cell Type Illustration Description Function Abundance (cells/μL)* Basophil Nucleus with two indistinct Releases histamine, which 0.5–1% of WBC A basophil is a polymorphonuclear cell with a polylobed nucleus and prominent, brightly metachromatic cytoplasmic granules. lobes; cytoplasmic granules promotes inflammation, and stain blue-purple; 10–12 μm heparin, which prevents clot in diameter formation Agranulocytes Lymphocyte Round nucleus; cytoplasm Produces antibodies and other 20–40% of WBC forms a thin ring around the chemicals responsible for nucleus; 6–14 μm in destroying microorganisms; A lymphocyte is an agranular cell with a very clear cytoplasm that stains pale blue. Nucleus is very large for the cell size and stains dark purple. diameter contributes to allergic reactions, graft rejection, tumor control, and regulation of the immune system Monocyte Nucleus round, kidney- Phagocytic cell in the blood; 2–8% of WBC shaped, or horseshoe- leaves the blood and becomes shaped; contains more a macrophage, which A monocyte has an irregular cell shape, an oval or kidney-shaped nucleus, cytoplasmic vesicles, and a high nucleus to cytoplasm ratio. cytoplasm than lymphocyte phagocytizes bacteria, dead does; 12–20 μm in diameter cells, cell fragments, and other debris within tissues Platelet Cell fragment surrounded by Forms platelet plugs; releases 150,000–400,000 A platelet is irregularly shaped and has no nucleus. plasma membrane and chemicals necessary for blood containing granules; 2–4 μm clotting in diameter *White blood cell counts are listed as percentage of total white blood cells. © McGraw Hill, LLC 12 Production of Formed Elements 1 Hematopoiesis or hemopoiesis: Process of blood cell production. Infant occurs in yolk sac of embryo, liver, thymus, spleen, lymph nodes, red bone marrow. After birth occurs in red bone marrow and lymphatic tissue; red bone marrow in adults is in ribs, sternum, vertebrae, pelvis, proximal femur, proximal humerus. © McGraw Hill, LLC 13 Production of Formed Elements 2 Stem cells: All formed elements derived from single population of hemocytoblasts. When a hemocytoblast divides, one daughter cell remains a hemocytoblast, while the other differentiates into either a myeloid stem cell or a lymphoid stem cell. Myeloid stem cells become: Proerythroblasts: Develop into red blood cells. Myeloblasts: Develop into basophils, neutrophils, eosinophils. Monoblasts: Develop into monocytes. Megakaryoblasts: Develop into platelets. Lymphoid stem cells become Lymphoblasts: Develop into lymphocytes. © McGraw Hill, LLC 14 Hematopoiesis Access the text alternative for slide images. © McGraw Hill, LLC 15 Erythropoietin (EPO) is a hormone released by the kidneys that stimulates red blood cell development. © McGraw Hill, LLC 16 Red Blood Cells (RBCs) Biconcave disc shape, 7.5 um in diameter. No nucleus in circulating RBCs. Flexible and capable of bending/folding, allowing them to pass through small vessels; move with the blood flow. Contain hemoglobin, lipids, ATP, carbonic anhydrase. © McGraw Hill, LLC 17 RBC Functions Transport oxygen from lungs to tissues: 98.5% attached to hemoglobin; 1.5% dissolved in plasma. Carbon dioxide transported 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. © McGraw Hill, LLC 18 Hemoglobin 1 Protein consisting of four subunits. Each subunit composed of a single polypeptide called globin. Globin bound to heme group; heme = red pigment containing one iron atom. Three types of hemoglobin. Embryonic and fetal: have greater attraction for oxygen than adult. Fetal production stops after birth. Adult. Oxyhemoglobin: iron in hemoglobin bound to oxygen; 4 per molecule of hemoglobin; bright red in color. Deoxyhemoglobin: hemoglobin not bound to oxygen; dark red. Carbaminohemoglobin: globin of hemoglobin bound to carbon dioxide. © McGraw Hill, LLC 19 Hemoglobin 2 Hemoglobin also transports nitric oxide (NO) that is produced by endothelial cells lining blood vessels; causes the relaxation of smooth muscle in blood vessels to decrease blood pressure. Poisons can affect hemoglobin, including carbon monoxide (CO); CO binds very strongly to the iron of hemoglobin to form carboxyhemoglobin which means less oxygen is being transported. © McGraw Hill, LLC 20 Hemoglobin 3 Access the text alternative for slide images. © McGraw Hill, LLC 21 Life History of Red Blood Cells Erythropoiesis: formation of red blood cells. Takes about 4 days. Production of red blood cells. Myeloid stem cells → proerythroblasts → early erythroblasts → intermediate erythroblasts → late erythroblasts → reticulocytes (released into the blood) → erythrocytes. Erythropoietin: hormone stimulates RBC production; produced by kidneys in response to low blood O2 levels (hypoxia). RBCs last 110-120 days in circulation, then rupture (hemolysis); hemoglobin in plasma broken down by macrophages. © McGraw Hill, LLC 22 Red Blood Cell Production 1. Hypoxia, decreased blood O2 levels, is detected by the kidneys. 2. The kidneys respond to hypoxia by increasing the secretion of erythropoietin. 3. Erythropoietin stimulates increased red blood cell production in the red bone marrow. 4. As red blood cell numbers increase in the blood, the blood’s ability to transport O2 increases allowing for more O2 to be delivered to the tissues of the body. Conversely, if blood O2 levels rise, less erythropoietin is released, and red blood cell production decreases. © McGraw Hill, LLC 23 Hemoglobin Breakdown 1 Macrophages take up hemoglobin released from hemolysis. Globin is broken down into amino acids. Heme broken down, iron released. Non-iron part of heme converted to biliverdin, then free bilirubin; free bilirubin is joined to glucuronic acid to form conjugated bilirubin (more water-soluble) which is added to the bile and passes in feces. © McGraw Hill, LLC 24 Hemoglobin Breakdown 2 1. Macrophages located in the spleen, liver, and other lymphatic tissue take up the hemoglobin released from ruptured red blood cells. Within a macrophage, lysosomal enzymes digest the hemoglobin to yield amino acids, iron, and bilirubin. 2. The globin part of hemoglobin is broken down into its component amino acids. Most of the amino acids are reused to produce other proteins. 3. The heme groups are broken down, releasing the iron atoms. Access the text alternative for slide images. © McGraw Hill, LLC 25 Hemoglobin Breakdown 3 4. Iron atoms released from heme are carried by the blood to red bone marrow, where they are incorporated into new hemoglobin molecules. 5. After the removal of the iron atoms, the non-iron part of the heme groups is first converted to biliverdin and then to bilirubin. The bilirubin is then released into the plasma, where it binds to albumin and is transported to liver cells. 6. This bilirubin, called free bilirubin, is taken up by the liver cells and conjugated, or joined, to glucuronic acid to form conjugated bilirubin, which is more water-soluble than free bilirubin. The conjugated bilirubin becomes part of the bile, which is the fluid secreted from the liver into the small intestine. Access the text alternative for slide images. © McGraw Hill, LLC 26 Hemoglobin Breakdown 4 7. In the intestine, bacteria convert bilirubin into the pigments that give feces its characteristic brownish color. 8. Some of these pigments are absorbed from the intestine, modified in the kidneys, and excreted in the urine, thus contributing to the characteristic yellowish color of urine (jaundice). Access the text alternative for slide images. © McGraw Hill, LLC 27 White Blood Cells 1 Have a nucleus and attract stain in slide preparations. Grouped into granulocytes and agranulocytes based on their appearance under microscope. Granulocytes have large granules and lobed nuclei; include neutrophils, eosinophils, basophils. Agranulocytes have granules not easily seen under scope; include lymphocytes, monocytes. © McGraw Hill, LLC 28 Standard Blood Smear Ed Reschke/Stone/Getty Images © McGraw Hill, LLC 29 Characteristics of White Blood Cells Function to protect the body from invading microorganisms and remove dead cells and debris from the body. Characteristics that help them perform their functions: Ameboid movement: directed movement similar to amoeba. Diapedesis: cells leave blood stream by becoming thin, elongating and moving 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. © McGraw Hill, LLC 30 Neutrophils Neutrophils: polymorphonuclear neutrophils (PMNs); stay in circulation 10 to 12 hours, then move into other tissues. Become motile, phagocytize bacteria, antigen- antibody complexes, and other foreign matter. Secrete lysozyme. Last 1 to 2 days. Account for 55 to 70% of the WBC. (a) Alvin Telser/McGraw Hill; © McGraw Hill, LLC 31 Eosinophils Eosinophils. Granules stain red with eosin. 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. Account for 1 to (b) BioPhoto Associates/Science Source; 4% of the WBC. © McGraw Hill, LLC 32 Basophils Basophils: least common. Granules stain blue or purple. Leave circulation and migrate through tissues, play a role in both inflammatory response and allergic reactions. Produce histamine (increases inflammation) and heparin (Inhibits blood clotting). Account for less than 0.5 to 1% of the WBC. (c) Alvin Telser/McGraw Hill © McGraw Hill, LLC 33 Lymphocytes Lymphocytes: produced in red bone marrow but then migrate to lymphatic tissues and proliferate. Responsible for antibody production (B cells) and direct destruction of virus and other microorganism infected cells (T cells). Account for 20 to 40% of the WBC. (d) Alvin Telser/McGraw Hill © McGraw Hill, LLC 34 Monocytes Monocytes: remain in circulation for 3 days, leave circulation and become macrophages that are phagocytic cells. Can break down antigens and present them to lymphocytes for recognition. Account for 2 to 8% of the WBC. (e) Ed Reschke/Stone/Getty Images © McGraw Hill, LLC 35 Platelets Cell fragments pinched off from megakaryocytes in red bone marrow. Surface glycoproteins and proteins allow adhesion to other molecules such as collagen. Important in preventing blood loss. Platelet plugs. Promoting formation and contraction of clots. Last 5-9 days. © McGraw Hill, LLC 36 19.5 Hemostasis Hemostasis: arrest of bleeding. Events preventing excessive blood loss. 1. Vascular spasm: Vasoconstriction of damaged blood vessels. Can occlude small vessels. Caused by thromboxanes from platelets and endothelin from damaged endothelial cells. 2. Platelet plug formation. 3. Coagulation or blood clotting. © McGraw Hill, LLC 37 Access the text alternative for slide images. © McGraw Hill, LLC 38 Coagulation Stages. Activation of prothrombinase. Conversion of prothrombin to thrombin. Conversion of fibrinogen to fibrin. Clotting 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. Eye of Science/Science Source Pathways. Extrinsic. Intrinsic. Result: blood clot. A network of threadlike fibrin fibers, trapped blood cells, platelets and fluid. © McGraw Hill, LLC 39 Clot Formation 1 1. Extrinsic pathway: Damaged tissues release a mixture of lipoproteins and phospholipids called thromboplastin, also known as tissue factor (TF) or factor III. Thromboplastin, in the presence of Ca2+, forms a complex with factor VII that activates factor X, which is the clotting factor that initiates the common pathway. Access the text alternative for slide images. © McGraw Hill, LLC 40 Clot Formation 2 2. Intrinsic pathway: Damage to blood vessels can expose collagen in he connective tissue beneath the endothelium of the blood vessel. When plasma factor XII comes into contact with collagen, factor XII is activated. Subsequently, activated factor XII stimulates factor XI, which n turn activates factor IX. Activated factor IX joins with factor VIII, platelet phospholipids, and Ca2 + to activate factor X, which, as stated n the extrinsic pathway description, initiates the common pathway. Although the extrinsic and intrinsic pathways were once considered distinct, we now know that the extrinsic pathway can activate tor VII complex from the extrinsic pathway can stimulate the formation of activated factor IX in the intrinsic pathway. Access the text alternative for slide images. © McGraw Hill, LLC 41 Clot Formation 3 3. Common pathway initiated: Activation of the extrinsic and/or intrinsic pathways results in the activation factor X. 4. Prothrombinase formed: On the surface of platelets, activated factor X, factor V, platelet phospholipids, and Ca2+ combine to form prothrombinase, or prothrombin activator. 5. Thrombin produced: Prothrombinase converts the soluble plasma protein prothrombin to the enzyme thrombin. Access the text alternative for slide images. © McGraw Hill, LLC 42 Clot Formation 4 6. Fibrin produced: A major function of thrombin is to convert the soluble plasma protein fibrinogen to the insoluble protein fibrin. Fibrin is the protein that forms the fibrous network of the blood clot. 7. Positive-feedback effects of thrombin: In addition, thrombin also stimulates factor XIII activation, which is necessary to stabilize the clot. Thrombin can also activate many of the clotting proteins, such as factor XI and prothrombinase. Thus, a positive-feedback system operates whereby thrombin production stimulates the production of additional thrombin. Thrombin also has a positive- feedback effect on platelet aggregation by stimulating platelet activation. Access the text alternative for slide images. © McGraw Hill, LLC 43 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. Prostacyclin: prostaglandin derivate from endothelial cells. Causes vasodilation and inhibits release of coagulating factors from platelets. Outside the body (for example, for transfusions): heparin, EDTA, sodium citrate. © McGraw Hill, LLC 44 Clot Retraction and Dissolution Clot retraction: clot condenses into compact structure. Platelets contain actin and myosin to aid in contraction. Serum is released as the clot contracts. Edges of the damaged blood vessel are pulled together, allowing fibroblasts and epithelial cells to begin the repair process Clot dissolves over time through process called fibrinolysis. Plasmin hydrolyzes fibrin; can be activated by t-PA, urokinase, or streptokinase. © McGraw Hill, LLC 45 19.6 Blood Grouping Transfusion: transfer of blood or blood components from one individual to another. Infusion: introduction of fluid other than blood. Transfusion success 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, Rh. © McGraw Hill, LLC 46 ABO Blood Groups Access the text alternative for slide images. © McGraw Hill, LLC 47 Transfusions and Matching Blood Types Type A has A antigen; blood has anti-B antibodies Type B has B antigen; blood has anti-A antibodies. Type AB has both A & B antigens; blood has no antibodies. Universal recipient. Type O has no antigens; blood has both A & B antibodies; Universal donor but can still cause a transfusion reaction. © McGraw Hill, LLC 48 Agglutination Reaction 1 a) No agglutination reaction. Type A blood donated to a type A recipient does not cause an agglutination reaction because the anti-B antibodies in the recipient do not combine with the type A antigens on the red blood cells in the donated blood. © McGraw Hill, LLC 49 Agglutination Reaction 2 b) Agglutination reaction. Type A blood donated to a type B recipient causes an agglutination reaction because the anti-A antibodies in the recipient combine with the type A antigens on the red blood cells in the donated blood. © McGraw Hill, LLC 50 Rh Blood Group Types. Rh-positive: Have these antigens present on surface of R BCs. (most common) Rh-negative: Do not have these antigens present. Hemolytic disease of the newborn (HDN). R- positive fetus, Rh-negative mother. Late in pregnancy, Rh antigens of fetus cross placenta (through a tear in placenta or during delivery); mother creates anti-Rh 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. © McGraw Hill, LLC 51 Hemolytic Disease of the Newborn (HDN) 1. In the mother’s first pregnancy with an Rh-positive fetus, there is often no problem. The leakage of fetal blood is usually the result of a tear in the placenta that takes place either late in the pregnancy or during delivery. Thus, there is not sufficient time for the mother to produce enough anti-Rh antibodies to harm the fetus. 2. At this point, however, sensitization occurs, and this can cause problems in a subsequent pregnancy. Once a person is sensitized and produces anti-Rh antibodies, they may continue to produce the antibodies throughout their life. 3. In a subsequent pregnancy with an Rh-positive fetus, because the mother is sensitized and produced anti-Rh antibodies, they may be present in the maternal blood. In addition, and especially dangerous if any fetal blood leaks into the mother’s blood, the mother rapidly produces large amounts of anti-Rh antibodies. 4. These anti-Rh antibodies can cross the placenta and cause agglutination and hemolysis of fetal red blood cells, resulting in HDN or erythroblastosis fetalis. Access the text alternative for slide images. © McGraw Hill, LLC 52 Because learning changes everything. ® www.mheducation.com © 2023 McGraw Hill, LLC. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw Hill, LLC.

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