Blood and Lymphatic Systems Pbp Summer 2014 Nikeshia Dunkelly-Allen nd323@nova.edu 1 Blood System Overview • Blood transports oxygen and nutrients to body cells • Blood removes carbon dioxide and other waste products from body cells for elimination 2 3 4 Composition of Blood • Plasma • 90 percent water = liquid portion of blood • Transports cellular elements of blood throughout circulatory system • Remaining portion = solutes • Electrolytes, proteins, fats, glucose, bilirubin, and gases • Most abundant solutes are plasma proteins: albumins, globulins, and fibrinogen 5 Composition of Blood • Solid components • Formed elements = cells + cell fragments • Erythrocytes, leukocytes, thrombocytes 6 Plasma Proteins • Albumins • Constitute about 60 percent of the plasma proteins • Help maintain normal blood volume and blood pressure • Help to maintain balance between fluid in the blood and fluid in the interstitial tissues 7 Plasma Proteins • Globulins • Constitute approximately 36 percent of plasma proteins • Alpha and beta globulins transport lipids (fats) and fat-soluble vitamins in blood • Gamma globulins are antibodies and function in immunity 8 Plasma Proteins • Fibrinogen • Constitutes approximately 4 percent of plasma proteins • Largest of plasma proteins • Essential in process of blood clotting 9 Blood Cells • Erythrocytes • Known as red blood cells (RBC) • Tiny biconcave-shaped disks • Thinner in center than around edges • No nucleus in mature red blood cell • Average life span = approximately 120 days • Main component = hemoglobin • Primary function = transport oxygen to cells of body 10 Blood Cells • Leukocytes • Known as white blood cells (WBC) • Larger than erythrocytes, but fewer in number • Mature WBC has a nucleus; does not have hemoglobin • Two categories = granulocytes + agranulocytes • Granulocytes have granules in their cytoplasm • Agranulocytes have no granules in their cytoplasm • Five different types of leukocytes within the categories 11 Blood Cells Granulocytes • Neutrophils • • • • Constitute approximately 60-70 percent of all WBCs Have multi-lobed nuclei Phagocytic in nature Do not absorb acid or base dye well • Remain fairly neutral color 12 Granulocytes • Eosinophils • • • • Constitute approximately 2-4 percent of all WBCs Have a nucleus with two lobes Increase in number in response to allergic reactions Stain a red, rosy color with an acid dye 13 14 Granulocytes • Basophils • • • • • Constitute less than 1 percent of all WBCs Have a nucleus with two lobes Secrete histamine during allergic reactions Secrete heparin – a natural anticoagulant Stain a dark blue with a base dye 15 16 Blood Cells Agranulocytes • Monocytes • • • • Constitute approximately 3-8 percent of all WBCs Largest of all white blood cells Have a kidney bean-shaped nucleus Phagocytic in nature 17 18 Agranulocytes • Lymphocytes • • • • • Constitute approximately 20-25 percent of all WBCs Have a large spherical-shaped nucleus Play important role in immune process Some lymphocytes are phagocytic Other lymphocytes produce antibodies 19 20 Cell Fragments • Thrombocytes • Small, disc-shaped fragments of very large cells called megakaryocytes • Also known as platelets • Contain no hemoglobin • Essential for normal clotting of blood 21 22 Blood Clotting • Clotting of blood = coagulation • Injury to blood vessel creates roughened area in vessel • Platelets come in contact with rough spot and disintegrate • Release substance called thromboplastin • Thromboplastin converts prothrombin into thrombin • In presence of calcium ions and other clotting factors • Thrombin converts fibrinogen into fibrin • Fibrin threads form a mesh that forms the clot 23 PATHOLOGICAL CONDITIONS The Blood 24 Malaria Plasmodium vivax is a protozoal parasite and a human pathogen. The most frequent and widely distributed cause of recurring (tertian) malaria, P. vivax is one of four species of malarial parasite that commonly infect humans. It is less virulent than Plasmodium falciparum, which is the deadliest of the four, and seldom fatal. P. vivax is carried by the female Anopheles mosquito, since it is the only sex of the species that bites. 25 Sickle Cell Anemia • Chronic hereditary form of hemolytic anemia in which RBCs become crescent-shaped in presence of low oxygen concentration • Crescent-shaped RBCs clump together forming thromboses which occlude small blood vessels, causing much pain for the individual 26 Sickle-cell 27 Hemophilia • Hemophilia is a rare genetic bleeding disorder caused by a shortage of certain clotting factors. Blood clotting factors are needed to help stop bleeding after a cut or injury to prevent spontaneous bleeding. Approximately 20,000 people in the United States suffer from hemophilia. 28 Leukemia • Leukemia is a cancer of the blood or bone marrow characterized by an abnormal proliferation of blood cells, usually leukocytes (white blood cells). Leukemia is a broad term covering a spectrum of diseases. In turn, it is part of the even broader group of diseases called hematological neoplasms. 29 Thalassaemia Thalassaemia is an inherited autosomal recessive blood disease. In thalassemia, the genetic defect results in reduced rate of synthesis of one of the globin chains that make up hemoglobin. Reduced synthesis of one of the globin chains can cause the formation of abnormal hemoglobin molecules, thus causing anemia, the characteristic presenting symptom of the thalassemias. 30 Blood doping • Blood doping is the practice of boosting the number of red blood cells (RBCs) in the bloodstream in order to enhance athletic performance. Because they carry oxygen from the lungs to the muscles, more RBCs in the blood can improve an athlete’s aerobic capacity (VO2 max) and endurance. 31 Lymphatic system 32 Lymphatic System Overview • Lymphatic system functions to produce antibodies and lymphocytes important to immunity • Lymphatic system also functions to maintain a balance of fluid in the internal environment 33 Lymphatic System Overview • Lymphatic system • Lymph fluid • Stems from the blood and tissue fluid • Lymph vessels • Similar to blood vessels – designed to return tissue fluid to bloodstream • Lymph nodes • Located along path of collecting vessels • Lymphatic organs • Thymus, spleen, and tonsils 34 Lymphatic System Overview • How lymph vessels differ from blood vessels • Lymph vessels do not form a closed circuit as does the cardiovascular system • Lymph vessels originate in intercellular spaces of soft tissues of the body 35 36 Lymphatic System Overview • Lymphatic system is an important part of the immune system • Immune system consists of: • • • • • • Bone marrow Thymus Lymphoid tissues Lymph nodes Spleen Lymphatic vessels 37 Lymph Vessels • Lymph capillaries • Smallest lymphatic vessels • Originate in tissue spaces as blind-ended sacs • Capillaries pick up accumulated interstitial fluid and return it to the blood • Fluid inside the lymphatic vessels is known as lymph 38 Lymph Vessels • Lymph vessels • • • • Larger than capillaries Receive lymph from lymphatic capillaries Valves prevent backward flow of fluid Transport fluid in only one direction • Away from the tissues toward the thoracic cavity 39 Lymph Vessels • Lymphatic ducts • Only points of entry of lymph into blood vessels of body • Right lymphatic duct • Receives lymph drainage from right side of head and neck • Also receives lymph drainage from right upper extremity, and right side of chest • Empties into right subclavian vein 40 41 Lymph Vessels • Lymphatic ducts • Thoracic duct • Receives lymph drainage from remaining regions of the body • Empties into left subclavian vein 42 Lymph Nodes • Collections of lymphatic tissue • Also called lymph glands • Located at intervals along course of lymphatic system vessels • Lymph passes through stationary lymph nodes • Old, dead cells and bacteria present in lymph are filtered out • Macrophages engulf and destroy any bacteria present 43 Axillary lymph nodes 44 45 Thymus • Located in mediastinum • Secretes thymosin – stimulates red bone marrow to produce T lymphocytes • T- cells important in immune response • T-cells mature in the thymus 46 47 Spleen • Located in upper left quadrant of abdomen: just below diaphragm, behind stomach • Largest lymphatic organ in the body • Plays an important role in the immune response • Filters blood • Macrophages of spleen remove pathogens from circulating blood • Macrophages also remove old red blood cells from circulation 48 49 Tonsils • Masses of lymphatic tissue • Located in protective ring, just under the mucous membrane • Surround the mouth and back of the throat • Serve as first line of defense from the external environment 50 Tonsils • Three groups • Pharyngeal tonsils or adenoids • Located near opening of the nasal cavity into pharynx (throat) • Palatine tonsils • Located on each side of the throat, near opening or oral cavity into pharynx • Commonly known as ‘the tonsils’ • Lingual tonsils • Located near the base of the tongue 51 52 Immunity • Natural • Immunity with which we are born; genetic • Acquired • Body has developed ability to defend itself against a specific agent • Can occur as result of having had the particular disease • Can be result of having received immunizations against a disease • Can be passive acquired immunity or active acquired immunity 53 Immunity • Passive Acquired Immunity • Acquired artificially by injecting antibodies into a person’s body • Protects person from a specific disease • Short-lived immunity – lasts only a few weeks • Example: gamma globulin • Given to individuals exposed to viruses such as measles and infectious hepatitis 54 Immunity • Active Acquired Immunity • Acquired naturally as result of having had a disease • Acquired artificially by being inoculated with a vaccine, antigen, or toxoid • Immunization = process of creating immunity to a specific disease 55 Immune Reaction • Immune reaction = Immune response • Defense mechanism of the body • Produces antibodies to destroy invading antigens and malignancies • Humoral immune response • B lymphocytes come in contact with specific invading antigens • Produce antibodies known as immunoglobulins 56 Immune Reaction • Cell-mediated immune response • T lymphocytes come in contact with specific invading antigens • T lymphocytes multiply rapidly and engulf and digest the antigen • Multiplication of cells produces memory cells • Memory cells provide the body with resistance 57 Hypersensitivity • Abnormal condition characterized by an excessive reaction to a particular stimulus • Body’s immune system fails to protect itself against foreign material • Allergic reaction is triggered by an allergen • Examples of allergens: • Ingested foods, penicillin and other antibiotics, grass, ragweed pollen and bee or wasp stings 58 Hypersensitivity • Hypersensitive reactions • Local reaction • Occurs at the site where treatment or medication was administered • Systemic reaction • Evidenced by generalized body symptoms such as runny nose, itchy eyes, hives, and rashes 59 Hypersensitivity • Hypersensitive reactions • Anaphylactic shock • Also known as anaphylaxis • Antigen-antibody reaction stimulates a massive secretion of histamine • Example causes: insect stings, contrast media containing iodide, aspirin, antitoxins prepared with animal serum, allergens used in testing 60 PATHOLOGICAL CONDITIONS Lymphatic System 61 Acquired Immunodeficiency Syndrome (AIDS) • Clinical conditions that destroy the body’s immune system in the last or final phase of a human immunodeficiency virus (HIV) infection, which primarily damages helper T cell lymphocytes with CD4 receptors 62 Hypersensitivity • Tissue damage resulting from exaggerated immune responses • • • • IgE-mediated-Type I hypersensitivity response Cytoxic-Type II hypersensitivity reaction Immune complex-mediated-Type III sensitivity response Delayed-Type IV hypersensitivity responses 63 Sources • Thomas Delmar Learning • Dr. Aziz Fall 2013 Lecture 64