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Chapter 18 Blood Blood Disorders Group Project Anemia Polycythemia Leukemia Mononucleosis (infectious) Hemophelia Sickle Cell Anemia Von Willebrand Disease Hemochromatosis Diamond Blackfan Anemia Deep Vein Thrombosis Thalassemia Prevention and treatment of Heart Diseases Stroke- Thromboembolyic condition Blood Unique tissue- The only fluid tissue in the human body Classified as a connective tissue Living cells = formed elements Non-living matrix = plasma Fibers- are not present, except during clotting Fibrin- are the fibers found during clotting Blood Physical characteristics and volume • • • Erythrocytes (red blood cells) make up 45% of blood Leukocytes (white blood cells) combined with Platelets (cell fragments) makes up less than 1% of blood Plasma (fluid matrix) makes up 55% of the blood Physical Characteristics of Blood Color range Oxygen-rich blood is scarlet red Oxygen-poor blood is dull, dark red pH must remain between 7.35–7.45 Blood temperature is slightly higher than body temperature Physical Characteristics of Blood Sticky- blood has a sticky feel to it Opaque- light does not pass through it Salty- to the taste Heavier than water and more viscous when pouring. 8% of the body weight is made up of blood Males- 5-6 liters Females- 4-5 liters Why do males have more? Functions of blood • Substance Distribution 1. Oxygen from the lungs and nutrients from the digestive system is carried to the body cells Waste transported away from the body cells Hormones- transported throughout the body to the target areas body temperature- maintained by absorption and distribution of heat 2. 3. 4. Functions of blood • 1) 2) 3) 4) Protection Body pH is maintained through the help of the blood. Fluid volume- proper balance is kept Blood loss- is prevented by the clotting process. Infection- prevented by the help of the white blood cells, antibodies and proteins. Plasma Proteins • Albumin – regulates osmotic pressure • Clotting proteins – help to stem blood loss when a blood vessel is injured • Antibodies – help protect the body from antigens Formed Elements Erythrocytes = red blood cells Leukocytes = white blood cells Platelets = cell fragments Erythrocytes (Red Blood Cells) The main function is to carry oxygen Anatomy of circulating erythrocytes Biconcave disks, more efficient- more surface area; dynamic changes for vessels Essentially bags of hemoglobin Anucleate (no nucleus) Contain very few organelles and no mitochondria (no oxygen needed); anaerobic respiration for energy Outnumber white blood cells 1000:1 Hemoglobin- (part of the RBC’s) Iron-containing protein found in RBC’s Makes up 35% of the RBC’s cell weight Binds strongly to oxygen, but doesn’t use it for energy Each hemoglobin molecule has four oxygen binding sites Each erythrocyte has 250 million hemoglobin molecules Red Blood Cell Count • Female- 4.3 - 5.2 million cells per cubic millimeter of blood • Male- 5.1 -5.8 million cells per cubic millimeter of blood • Why do males have more? Function of RBC’s Carries O2 from the lungs to the body cells Hemoglobin- binds to the oxygen to carry it (heme to O2; globin to CO2) Iron- is important in the making of the “heme” part of hemoglobin (lack of iron =anemia) Carbon dioxide- 20% of CO2 combines with hemoglobin (globin part) Hematopoiesis Blood cell formation Occurs in red bone marrow (adults= diploe of flat bones All blood cells are derived from a common stem cell (hemocytoblast) Hemocytoblast differentiation Lymphoid stem cell produces lymphocytes Myeloid stem cell produces other formed elements RBC’s eject nucleus, and most of their organelles when matured Control of Erythrocyte Production Rate is controlled by a hormone (erythropoietin) Kidneys produce most erythropoietin as a response to reduced oxygen levels in the bloodhypoxia; or an increase in tissue demands for O2 (aerobic activity) Homeostasis is maintained by negative feedback from blood oxygen levels Decline in number of RBC’s will also cause hypoxia Testosterone- will also increase RBC production which is why males will have more RBC’s Control of Erythrocyte Production Figure 10.5 Nutrients needed for production of RBC’s 1. 2. 3. Iron 65% of the body’s iron is found in the hemoglobin Free iron- is poisonous in the body Iron not in the hemoglobin is stored in proteins B12 and folic acid- also important in RBC production Fate of Erythrocytes (RBC’s) Unable to divide, grow, or synthesize proteins- No Nucleus Wear out in 100 to 120 days (lifespan) When worn out, are eliminated by phagocytes in the spleen or liver Lost cells are replaced by division of hemocytoblasts Leukocytes and White blood cells Leukocyte Levels in the Blood Normal levels are between 4,000 and 11,000 cells per millimeter They have nuclei and all organelles Abnormal leukocyte levels Leukocytosis Above 11,000 leukocytes/ml Generally indicates an infection Leukopenia Abnormally low leukocyte level Commonly caused by certain drugs WBC’s: Protective mobile army Crucial in the body’s defense against disease These are complete cells, with a nucleus and organelles Able to move into and out of blood vessels (diapedesis) Can move by ameboid motion-(pseudopods) Can respond to chemicals released by damaged tissues Their numbers can double within a few hours in order to fight disease/sickness Types of Leukocytes Granulocytes Granules in their cytoplasm can be stained Include neutrophils, eosinophils, and basophils Granulocytes Neutrophils most numerous type of WBC’s chemically attracted to inflamed sites Act as phagocytes at active sites of infection especially against bacteria and fungi Eosinophils found in intestines and on skin Found in repsonse to allergies and parasitic worms Phagocytotic to foreign bodies instead of bacteria Granulocytes Basophils Have histamine/heparin containing granules Initiate inflammation and aid in migration of other WBC’s Least numerous type of WBC’s Types of Leukocytes Agranulocytes Lack visible cytoplasmic granules Include lymphocytes and monocytes Agranulocytes Lymphocytes Found in lymph tissue Play an important role in the immune response T-cells fight virus infection (T-helper cells) B-cells produce antibodies Monocytes Largest of the white blood cells Function as macrophages Important in fighting chronic infection Production of Leukocytes • Hormonally stimulated • Granulocytes and agranulocytes will take a different path • Life span will vary greatly; depends on wars against bacteria etc. Thrombocytes (aka Platelets) They are cell fragments; not complete cells Needed for the clotting process Normal platelet count = 250,000500,000/mm3 They are regulated by hormones Anucleated (no nucleus) and will only live for about 10 days Blood Plasma Composed of approximately 90 percent water Includes many dissolved substances (over 100 different solutes) Nutrients Salts (metal ions) Respiratory gases Hormones Proteins- makes up 8%; mostly produced by the liver Waste products Hemostasis Stoppage of blood flow Result of a break in a blood vessel Hemostasis involves three phases 1. Vascular spasms 2. Platelet plug formation 3. Coagulation Vascular Spasms Anchored platelets release serotonin Serotonin causes blood vessel muscles to spasm Spasms narrow the blood vessel, decreasing blood loss Platelet Plug Formation Collagen fibers are exposed by a break in a blood vessel Platelets become “sticky” and cling to fibers Anchored platelets release chemicals to attract more platelets Platelets pile up to form a platelet plug Coagulation ( aka blood clotting) Injured tissues release thromboplastin Result is a mesh of fibrin that traps blood cells, sealing the hole until the tissue can be repaired Most chemicals needed for clotting is in the blood; just need to change balance. Procoagulant- chemicals that enhance or promote clotting Anticoagulants- chemicals that inhibit or prohibit blood clotting Coagulation Anticoagulants are normally dominant Thromboplastin (released from the platelets) call other platelets to the area and make procoagulants dominant Calcium ions Ca++ are also needed Clotting normally takes 3-6 minutes May be faster in emergencies Blood Clotting Blood usually clots within 3 to 6 minutes The clot remains as endothelium (vessels tissue) regenerates Platelets and fibrin are pulled tighter squeezes out the serum in a process known as synerisis (plasma – the clotting agents) Pulls vessel closer together for repair The clot is broken down after tissue repair Fibroblast- help to form a connective tissue patch Fibrinolysis The process of getting rid of blood clots when you no longer need them Plasmin- is the protein that is in charge (clot buster) Begins within 2 days after the clot is formed Undesirable Clotting Thrombus A clot in an unbroken blood vessel Can be deadly in areas like the heart Embolus A thrombus that breaks away and floats freely in the bloodstream Can later clog vessels in critical areas such as the brain Bleeding Disorders Thrombocytopenia Platelet deficiency Even normal movements can cause bleeding from small blood vessels that require platelets for clotting Hemophilia Hereditary bleeding disorder Normal clotting factors are missing Blood Groups and Transfusions Large losses of blood have serious consequences Loss of 15 to 30 percent causes weakness Loss of over 30 percent causes shock, which can be fatal Transfusions are the only way to replace blood quickly Transfused blood must be of the same blood group Human Blood Groups Blood contains genetically determined proteins A foreign protein (antigen) may be attacked by the immune system Blood is “typed” by using antibodies that will cause blood with certain proteins to clump (agglutination) Human Blood Groups There are over 30 common red blood cell antigens The most vigorous transfusion reactions are caused by ABO and Rh blood group antigens ABO Blood Groups Based on the presence or absence of two antigens Type A Type B The lack of these antigens is called type O ABO Blood Groups The presence of both A and B is called type AB The presence of either A or B is called types A and B, respectively http://www.redcrossblood.org/learn-about-blood/blood-types Rh Blood Groups Named because of the presence or absence of one of eight Rh antigens (agglutinogen D) Most Americans are Rh+ Problems can occur in mixing Rh+ blood into a body with Rh– blood Rh Dangers During Pregnancy Danger is only when the mother is Rh– and the father is Rh+, and the child inherits the Rh+ factor Rh Dangers During Pregnancy The mismatch of an Rh– mother carrying an Rh+ baby can cause problems for the unborn child The first pregnancy usually proceeds without problems The immune system is sensitized after the first pregnancy In a second pregnancy, the mother’s immune system produces antibodies to attack the Rh+ blood (hemolytic disease of the newborn) Blood Typing Blood samples are mixed with anti-A and anti-B serum Coagulation or no coagulation leads to determining blood type Typing for ABO and Rh factors is done in the same manner Cross matching – testing for agglutination of donor RBCs by the recipient’s serum, and vice versa Developmental Aspects of Blood Sites of blood cell formation The fetal liver and spleen are early sites of blood cell formation Bone marrow takes over hematopoiesis by the seventh month Fetal hemoglobin differs from hemoglobin produced after birth