Blood and Lymphatic Systems PBP Summer 2017Presented by Fabian Omenankitifomenankiti@bison.howard. edu
Blood System Overview • Blood transports oxygen and nutrients to body cells • Blood removes carbon dioxide and other waste products from body cells for elimination
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
Composition of Blood • Solid components • Formed elements = cells + cell fragments • Erythrocytes, leukocytes, thrombocytes
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
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
Plasma Proteins • Fibrinogen • Constitutes approximately 4 percent of plasma proteins • Largest of plasma proteins • Essential in process of blood clotting
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
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
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
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
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
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
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
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
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
Malaria Plasmodium vivax is a protozoalparasite 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.
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
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.
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.
Thalassaemia Thalassaemia is an inherited autosomal recessiveblood 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.
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.
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
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
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
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
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
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
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
Lymph Vessels • Lymphatic ducts • Thoracic duct • Receives lymph drainage from remaining regions of the body • Empties into left subclavian vein
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
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
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
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