Blood-1

1. Lesson # 3 (Chapter 19) Blood-1 Objectives: 1- To describe the general characteristics of blood and its major functions.2- To describe the types of blood cells. 3- To describe the functions of red blood cells. 4- To list the blood types and explain the importance and basis of blood typing. 5- To discuss the reaction sequences responsible of blood clotting.

2. Introduction to the Cardiovascular System • Heart The muscular pump that makes blood to circulate through the blood vessels. The Cardiovascular System Blood vessels The plumbing that ensure the proper routing of blood to its destination. It transports substances from place to place in the body. Blood It is the liquid medium in which these substance travel.

3. Blood • Blood is specialized fluid of connective tissue, which contains cells suspended in a fluid matrix. Functions of Blood 1- Transport of dissolved substances • Oxygen and carbon dioxide, nutrients, hormones, immune system components , waste products. 2- Regulation of pH and ions Blood eliminates deficiencies or excesses of ions. It also absorbs and neutralizes acids generated by active tissues. 3- Restriction of fluid losses at injury sites Blood contains enzymes and other substances that initiate the process of clotting. 4- Defense against toxins and pathogens Blood transports white blood cells that migrate into other tissues to fight infections and to remove debris. Blood also contains and delivers the antibodies. 6- Stabilization of body temperature Blood absorbs the heat generated by active skeletal muscles and distributes it to other tissues. If body temperature increases, the heat is lost through the skin blood vessels. If body temperature is too low, the warm blood is directed to the brain and other temperature-sensitive organs.

4. Composition of Whole Blood Plasma (46-63%) Formed elements (37-54%)

5. They are made in the liver. Functions: Major contributors to osmotic pressure of plasma. Transport lipids and steroids hormones. It is also made in the liver. Functions:Essential component of clotting system. They are produce by white blood cells (lymphocytes) and by the liver. Functions: Antibodies. Transport ions, hormones and lipids. The Composition of Plasma Plasma is 92% water in which are dissolved proteins and a mixture of other materials (hormones, nutrients, wastes and electrolytes). Albumins (60%) Globulins (35%) PLASMA PROTEINS (7%) Fibrinogen (4%) Regulatory proteins (< 1%) Enzymes, proenzymes and hormones.

6. Electrolytes They are ions produce by the dissociation of salts in water: Na+, K+, Ca2+, Mg2+, Cl-, HCO3-, HPO4-, SO42- Functions: A normal ion composition is essential for vital cellular activities. Ions contribute to osmotic pressure of body fluids. Organic Nutrients OTHER SOLUTES (1%) Lipids (fatty acids, cholesterol, glycerides), carbohy-drates (glucose), and aminoacids. Functions: They are used for ATP production, growth and cell maintenance. Organic waste They are carried to sites of breakdown or excretion. Ex: Urea, uric acid, creatinine, bilirubin, ammonium ions.

7. The Cardiovascular System GasExchange Systemic Pulmonary Circuit Circuit Capillary Lung Venule Arteriole Pulmonary arteries Pulmonary veins O2 poor, CO2 rich blood O2 rich, CO2 poor blood Wastes Nutrients O2 CO2 CO2 O2 Venae cavae Aorta Capillary Tissue Venule Arteriole

8. BHP BOP BOP > BHP BHP > BOP Venule Arteriole Wastes Nutrients CO2 1- Blood Hydrostatic Pressure (BHP) pushes water outside the blood vessels O2 Tissue 2- Blood Osmotic Pressure (BOP) pulls water back to the blood vessels Blood Osmotic Pressure of the blood depends on: 1- Electrolytes ( mainly sodium ions) 2- Proteins (mainly albumin) 3- Erythrocytes

9. If the osmolarity of the blood is too high, the blood stream absorbs too much water, the blood volume raises, and blood pressure increases. Ex: Patients with high blood pressure must reduce the intake of salt in the diet. If the osmolarity of blood drops too low, too much water remains in the tissues and they become swollen (edematous). • Kwashiorkor • Children with severe protein deficiency.

10. Formed Elements of Blood Monocyte Small lymphocyte Neutrophil Platelets Eosinophil Small lymphocyte Erythrocyte Neutrophil Monocyte Large lymphocyte Neutrophil Basophil

11. Red Blood Cells or Erythrocytes Red blood cells constitute 99.9% of all the formed cell in blood. • Number of RBCs in 1 microliter of whole blood: • Male: 4.5–6.3 million • Female: 4.2–5.5 million • Packed cell volume (PCV) or Hematocrit). It is the percentage of RBCs in centrifuged whole blood: • Male: 40–54% • Female: 37–47% Erythrocytes lack of nucleus and other organelles and live only an average of 120 days. They are biconcave discs, thick in the outer edges and thin in the center. They contain the hemoglobin, which transport O2 and CO2.

12. Hemoglobin Hemoglobin is a protein that gives the RBCs their color and name. Each RBC contains about 280 million molecules of hemoglobin (33% of the cytoplasm). • Normal hemoglobin (adult male): 14–18 g/dL whole blood • Normal hemoglobin (adult female): 12–16 g/dL, whole blood

13. Fe2+ • Hemoglobin has a complex quaternary structure consisting of four globular protein subunits. • Each chain contains one molecule or group heme. • Each heme contains one iron ion, which associates easily with oxygen (oxyhemoglobin) OR dissociate easily from oxygen (deoxyhemoglobin). Hb + O2 4 HbO2 Deoxyhemoglobin Oxyhemoglobin Each RBC contains about 280 million molecules of hemoglobin. Each RBC potentially can carry more than a billion molecules of O2 (280 x 4)

14. Hemoglobin Conservation and Recycling Macrophage in spleen, liver, bone marrow BONE MARROW Fe2+ is transported in circulation by transferrin Fe2+ RBC formation Amino- acids 120 days average life span (90%) Heme Bilirubin-derived products Bilirubin-derived products Urobilins, Stercobilins Bilirubin Bilirubin Biliverdin Bilirubin Bilirubin Indirect or unconjugated bilirubin. It increases in accelerated erythrocyte hemolysis (erythroblastosis fetalis, hemolytic anemia), and hepatocellular disease 10% Hemolysis + Albumin BLOOD PLASMA KIDNEYS LIVER Hb Excreted in bile Absorbed into the circulation If is called hemoglobinuria Direct or conjugated bilirubin. It increases in obstruction of the biliary ducts (cancer of pancreas’ head), gallstones or hepatocellular diseases such as cirrhosis or hepatitis. Eliminated in urine LARGE INTESTINE SMALL INTESTINE Eliminated in feces

15. Iron Metabolism When iron is released into the blood stream, it binds to transferrin, a plasma protein Excess transferrins, are removed in the liver and spleen and the iron is stored in two special proteins-iron complex: ferritin and hemosiderin. Transferrin Iron Plasma protein that transports iron Ferritin Protein-iron complex that stores iron Hemosiderin Protein-iron complex that stores iron

16. RBC Production Erythrocytes have no repair mechanisms because they lack of nucleus and other organelles. They live only an average of 120 days. • About 1% of circulating RBCs are replaced everyday. • In this process, about 3 million new RBCs enter the blood stream each second. Erythrocyte production is called erythropoiesis, which normally takes 3 to 5 days. White blood cells (leucopoiesis) Myeloid stem cell Pro- erythroblast Erythroblast Reticulocyte Erythropoiesis takes place in the red bone marrow. Normoblast Mature Red Blood Cell Day 1 Day 3 Day 4 Day 5-7 Circulation Nucleus Synthesis of hemoglobin (80%). Erythropoiesis requires: Erythropoiesis is stimulated by: • Aminoacids • Iron • Vitamins B12, B6, and folic acid • Erythropoietin • Thyroxine • Androgens • Growth hormone

17. Blood Types Blood types and transfusion compatibility are a matter of interaction between antigens and antibodies. Antigens They are foreign substances that are able to trigger an immune response. Most of antigens are proteins. Antibodies They are proteins produced by cells of the immune system, which are able to recognize an interact with the corresponding antigens. Y Y Y Y Y Y Plasma cell Y Antigens Y Y Y Y

18. Antigen-antibody reaction is specific, meaning that the antibodies can recognize only the corresponding antigens. Y Y Y Y Y Y Antigens Plasma cell Plasma cell Y Antigens Y Y Y Y C C C C C C C C C C Antigens Plasma cell

19. The plasma membrane of the cells contains glycoproteins (surface markers) on the outer surface that can act as antigens. That means that they can trigger an immune response and can interact with the corresponding antibodies. Surface markers are genetically determined and are different in every person. They are responsible for transplant rejection. C C C C C Transplant rejection is a process in which a transplant recipient's immune system attacks the transplanted organ or tissue.

20. Blood types and transfusion compatibility are a matter of interaction between plasma antibodies and surface antigens in the erythrocytes. The plasma membrane of the erythrocytes contains glycoproteins on the outer surface that can act as antigens. That means that they can interact with the corresponding antibodies. ABO Blood Group Type A Type B Type A B Type O

21. Blood Types are Genetically Determined Genotype Blood Type (Phenotype) Genotype Blood Type (Phenotype) A A A A A i B B B B B i O A B A B i i

22. Plasma contains antibodies against surface antigens that are not present on self cells. That is why foreign tissues are rejected by the immune system. Plasma contains antibodies against surface antigens that are not present on self red blood cells. Neither anti-A nor anti-B antibodies Anti-A and anti-B antibodies Anti-B antibodies Anti-A antibodies

23. When antibodies attack, the foreign cells agglutinate (clump together). This process is called agglutination. + Ab The antigens that determine the blood types are called agglutinogens, and the corresponding antibodies are called agglutinins

24. ABO Blood Typing Control Blood Type A B AB O

25. Rh Blood Group The Rh blood group is named for the rhesus monkey, the animal in which the Rh antigens were discovered in 1940. D D D D D D D D This group include numerous antigens (C, D, E). Antigen D is by far the most reactive and it is used for Rh typing. Genotypes DD or Dd Genotype dd Rh + Rh - No anti-D antibodies No anti-D antibodies

26. ABO and Rh Blood Typing Control Anti-A Anti-B Anti-D Control Anti-A Anti-B Anti-D A- AB- AB+ A+ B- O- B+ O+

27. Transfusion Reaction The agglutinated RBCs lodge in smaller blood vessels and cut of the blood flow to vital organs. Blood from type A donor Free hemoglobin can block the kidney tubules and produce death from acute renal failure within a week or so. Type B (anti-A) recipient Donor RBCs agglutinated by recipient plasma Agglutinated RBCs block small vessels

28. Hemolytic Disease of Newborn leaves Rh- mother Rh antigen Second Rh+ fetus Rh+ fetus Uterus Anti-D antibody Amniotic sac and chorion Placenta (a) First pregnancy (b) Between pregnancies (c) Second pregnancy Rh antibodies attack fetal blood causing severe anemia and toxic brain syndrome (Hemolytic Disease of the New Born).