Chapter 12 Chapter 12 The Lymphatic System and the Blood Applied Learning Outcomes Use the terminology associated with the blood and lymphatic system Learn about the following: Blood components Lymphatic system components Immune system function Mechanisms of immunization and vaccination Understand the aging and pathology of the lymphatic system Overview Chapter 12 The Lymphatic System and the Blood Blood is composed of plasma and formed elements. Blood transports materials needed for body homeostasis. There are three blood cell types: RBCs, WBCs, and platelets. The lymphatic system regulates body fluids and the immune system. Overview Embryos lack blood until week 5 of development. Have pockets of special cells that start producing blood 2 weeks after the blood vessels form from the mesoderm. Plasma the fluid portion of the blood. Cells and other material are transported in Composed of 90% water, 7% protein, 1% minerals, and 2% other materials like gases, chemical signals, and nutrients. Primary gases are oxygen, carbon dioxide, and nitrogen Blood proteins assist with healing and immune system 55% of blood volume is plasma 45% is formed elements (Blood cells) Overview Three categories of blood cells: 1.erytrhocytes (red blood cells) RBC 2. leukocytes (white blood cells) WBC 3.thrombocytes (platelets) Hematocrit (packed cell volume (PCV) the percentage of packed RBCs in a unit volume of whole blood Measure it by putting whole blood in a tube inside a centrifuge. Spin the blood until the RBCs collect as a pellet at the bottom of the tube. WBCs and Platelets can be found the same way. Overview Lymphatic system 1.made up of tissues that produce, store, and carry lymphocytes throughout the body. 2. responsible for fighting infection and controlling fluid levels in tissues. 3.Includes bone marrow, specialized organs, and network of thin tubes 4.Develops from mesoderm around week 5 5. Its full growth and function are not complete until after birth Blood Cells Chapter 12 The Lymphatic System and the Blood RBCs contain the protein hemoglobin. Blood type is another feature of RBCs. Classifications are types A, B, and D The A and B proteins make up the ABO blood group system The D protein is the Rh factor The five types of WBCs are neutrophils, lymphocytes, eosinophils, monocytes, and basophils. WBCs are categorized as granulocytic or agranulocytic. Red Blood Cells Lack a nucleus Immature RBC are called reticulocytes RBCs live maximum of 120 days Contain hemoglobin that transports oxygen and carbon dioxide Women average 4.8 million RBC/ cubic mm of blood Men average 5.4 million RBC/ cubic mm of blood Complete blood count (CBC) or Full blood count (FBC) Series of tests that examine components of the of blood Also known as a Hemogram Red Blood Cells Blood Type: Way of categorizing RBCs according to variation of proteins on the cell membrane surface. The proteins A and B make up the ABO Blood group system People with O type blood do not have protein A or B on their cell membrane surface The D protein is called the Rh factor. You are Rh+ if you have the D protein Rh- people lack the D protein. Blood Types Makes Type antibodies accept give to A against BA, OA, AB B against AB, O B, AB AB no antibodiesA,B, AB,AB universal against any blood and O recipient O against A and B O A,B, AB, universal & O donor Blood Types Rh+ have protein D on cell membrane. Rh- lack protein D on cell membrane. Erythroblastosis fetalis when a pregnant womans body produces an immune response against Rh positive blood from her developing fetus. Only affects Rh- mothers. They are now given a drug called Rhogam during and after pregnancy. It causes the mothers body to destroy any antibodies she has built up against Rh- blood. White Blood Cells Five types of WBCs: 1.Neutrophils most abundant (40-75%) 2.Lymphocytes (20-50%) 3.Eosinophils (5%) 4.Monocytes (1-5%) 5.Basophils (0.5%) Differential WBC count evaluates the percentage of each WBC type. Important indicator of infectious diseases Between 4000 to 11,000 WBC/cubic mm White Blood Cells Granulocytes (polymorphonuclear WBCs) Have granules in cytoplasm Produce specialized secretions for fighting infections Nucleus is polymorphic (unusual shape) Neutrophils, eosinophils, and basophils are examples. Agranulocytes (mononuclear WBCs) Lack visual granules Play role in the immune system Lymphocytes and monocytes are examples. Lymphocytes divided into two types: B-lymphocytes and T-lymphocytes Platelets Not true cells Cell fragments Come from larger cells called Megakaryocytes Megakaryocytes are covered with many proteins that allow platelets to stick to a variety of materials. Stickiness helps reduce blood flow to a damaged area 250,000 to 500,000 platelets /cubic mm of blood Blood Cell Function Chapter 12 The Lymphatic System and the Blood RBCs transport atmospheric gases throughout the body: oxygen from the lungs to the cells; carbon dioxide from the cells to the lungs WBCs granulocytes produce secretions that kill microorganisms; lymphocytes are agranulocytes that produce the bodys immune response Blood Cell Function RBCs carry oxygen from the lungs to the body cells Oxygen attaches to the hemoglobin. Four oxygen molecules bind to one hemoglobin molecule. RBCs carry carbon dioxide from body cells to the lungs. Carried three ways in the blood 1.10% of the CO 2 never enter the RBC- it is transported as a gas in the blood plasma 2.22% of CO 2 released by tissues is carried by Hemoglobin 3.Rest of CO 2 is transported as a bicarbonate ion RBCs stimulate formation of bicarbonate ions using enzyme Carbonic anhydrase it converts carbon dioxide and water into bicarbonate ions. Important in maintaining blood pH. Blood Cell Function WBCS -most of their functions are involved in repairing the body and fighting infectious disease. Granulocytes: contain granules of toxic chemicals that are released to kill microorganisms and regulate reactions to foreign materials in the body. Neutrophils- pass through capillaries into infected tissues they adhere to injured tissues and use phagocytosis to engulf bacteria and damaged cells. can secrete potent antibiotics Eosinophils- produce secretions that defend against large parasitic organisms. Secretions kill protista and worms increase in Eosinophils indicated parasitic infection. Blood Cell Function Granulocytes: contain granules of toxic chemicals that are released to kill microorganisms and regulate reactions to foreign materials in the body. Basophils are least common WBC they secrete histamine stimulates the immune response Overproduction of histamine causes runny nose, sneezing, and watery eyes Special basophil- Mast cell are responsible for inflammation of tissues. Blood Cell Function Agranulocytes: Monocytes- once they leave bone marrow develop into either: circulating monocytes tissue monocytes (macrophages) Circulating moncytes major role is to detect infectious agents traveling in the blood Tissue macrophages remove dead cells and attack microorganims that are difficult to kill, such as fungi. Platelets Involved in the Blood clotting process Carry out a two-step process: the platelets adhere to an injured area followed by the activation of clot formation. Intact vessels secrete a lipid called prostacyclin which prevents platelet activation. Damage to a blood vessel or body tissue produces a reaction The Clotting cascade: tissue or blood vessel damaged 1.Release collagen and clotting factors 2.Causes platelets to adhere to damaged tissue and to each other 3.Causes conversion of prothrombin into thrombin. 4.Thrombin converts to a protein called fibrinogen into fibrin 5.Fibrin forms sticky meshwork (beginning of clot) 6.Sticky meshwork forms temporary barrier- prevents blood loss, 7.Impedes passage of microorganisms 8.Scab that forms is an example of a clot 9.Clots not permanent, temporarily patch until it is repaired 10.Plasminogen converted to plasmin-it is an enzyme that dissolves the clot. Cut in skin sticky platelets clotting factors (prothrombin, prothrombin activator, calcium) causes the conversion to thrombin + fibrin forms a sticky meshwork that fibrinogen adheres to thrombocytes and other blood components. Blood Clotting Cascade Blood Cell Formation Chapter 12 The Lymphatic System and the Blood Blood Cell Formation All blood cells in adults are produced in the bone marrow. In the embryo, the liver is responsible for blood cell formation. All red and white blood cells are derived from a type of stem cell called hematopoietic or multipotent stem cell. Hematopoietic cells can develop into lymphoid stem cells or myeloid progenitor Lymphoid progenitor cells give rise to WBCs Myeloid progenitor cells give rise to platelets, RBCs, WBCs Blood Cell Formation Erythropoiesis is the process by which RBCs are formed. RBCs mature in approximately 7 days and live about 120 days. Aging RBCs are destroyed in the liver and spleen. The digestive system then removes the hemoglobin as a yellowish chemical called bilirubin. WBCs live from 13 to 20 days. Immature WBCs are released from bone marrow. They are called bands or stabs. Then they are destroyed by the lymphatic system. Lymphatic System Chapter 12 The Lymphatic System and the Blood Composed of lymphatic glands, lymph nodes, and lymph vessels Immune function provided by WBCs Immunity is either innate or acquired The body has a primary and a secondary immune response Lymphatic System Structural components are Lymphatic vessels Lymph nodes (lymph glands) Spleen Thymus Tonsils WBCs Lymph Lymph vessels are thin ducts that carry lymph. They drain excess fluid that accumulates in tissue preventing edema (swelling) Lymph does a variety of jobs: Removal of foreign bacteria and materials Transports fat from digestive system Moves mature lymphocytes (WBCs) to the blood Lymphatic System Lymphatic trunk is a network of lymph vessels that drains regions of the body. drains lymph from larger areas of the body has collections of small swollen regions of lymphatic tissue Tonsils are one of a pair of clusters of lymphatic tissue, located in the throat. Peyers patches is another cluster of lymphatic tissue located in the intestines Lymphatic System Lymph nodes are complex collections of lymphatic tissue covered by connective-tissue capsules. Four components making them up: Blood vessels lymphatic sinuses lymphocytes filler tissue (stroma) Hilum is region of the lymph node where the blood vessel enters and exit. Trabeculae is partitions that divide the lymph node into regions. They contain B and T lymphocytes. Macrophages are found in the lymphatic sinuses. Lymphatic System Spleen is divided into two functional regions: Red pulp - it is a storage area for RBCs Also responsible for removing old or damaged RBCs from circulation. White pulp - region of lymphatic tissue contains B and T lymphocytes Thymus gland located above the heart larger during childhood begins to shrink during puberty loses some of its functions as you age. Immune Response Is a complex array of anatomical structures and cellular events that protects the body from foreign chemicals called antigens. The immune system uses two mechanisms to respond to disease: Innate immunity Aquired immunity Innate immunity nonspecific immunity skin, mucus membranes, saliva, stomach acid, tears, fever Interferons are a group of proteins that cells produce following a viral infection. They bind to other cells and inhibit viral replication. Complements are a group of plasma proteins that can be activated to destroy microorganisms. Monocytes (WBCs) travel the body destroying any material that is not recognized as part of the body. Natural killer (NK) cells are specialized T-lymphocytes that secrete proteins that kill tumor cells and microorganisms. Immune Response Immunization and Vaccination Chapter 12 The Lymphatic System and the Blood Natural immunity is the unintentional stimulation of the immune system. Artificial immunity is the use of therapy to stimulate the immune system. Immunization is a medical strategy for enhancing the bodys natural immune response. Vaccines are immunizations that produce active immunity. Active immunity is caused by exposure to antigens. Passive immunity is produced by providing the body with antibodies. Wellness and Illness over the Life Span Chapter 12 The Lymphatic System and the Blood Anemia is a common ailment of the blood that is actually a group of various RBC disorders. Most cases of anemia involve a decrease in the number of RBCs. Genetic disorders can lead to the production of abnormal blood cells. Blood clotting is also subject to a variety of disorders. WBCs are prone to deficiencies and cancers. Most deficiencies are due to malnutrition and exposure to hazardous chemicals. Disorders of the lymphatic system affect its ability to drain body fluids and carry out immune functions. Wellness and Illness over the Life Span Chapter 12 The Lymphatic System and the Blood Much of the aging of the blood and lymphatic system is due to changes in the digestive and endocrine systems. WBC function is likely to become abnormal with age. Immobility and weakening of the skeletal muscles is another feature of aging. Summary Chapter 12 The Lymphatic System and the Blood Plasma brings many nutrients to cells and carries away wastes. RBCs carry oxygen to cells and remove carbon dioxide. WBCs form part of the immune system that protects the body from disease and assists with injury repair. The lymphatic system uses its own components and cells derived from the blood to prevent and fight off infections. Aging brings about changes to the immune system that make people more susceptible to infections and less likely to rapidly heal injuries.