**The Vital Fluid: Understanding Blood Composition and Functions** This informative guide delves into the intricate deta

1. Blood

2. Blood • Connective tissue • Formed elements suspended in intercellular matrix (plasma) • Cells • Cell fragments • Only liquid tissue • 4-5L female • 5-6L male • 8% of total body weight • slightly alkaline pH 7.35 – 7.45

3. 3 main functions • transportation • carries O2 and nutrients to cells • CO2 and nitrogenous wastes from tissues to lungs and kidneys • Carries hormones from the endocrine glands to target tissues

4. Regulation • Regulate body temp. • Removes heat from areas and transporting to other regions (skin) • Fluid and electrolyte balance • pH reg. • Protection • Clotting prevents fluid loss • Phaogcytic WBC’s destroy microorganisms • Antibodies help protect against disease

5. Composition of Blood • Plasma – 55% • Liquid portion • 90% H2Ocontains >100 different organic and inorganic solutes • Plasma Proteins • Most abundant • Normally not used for energy • 3 major classes • Albumins – 60% ~ Help maintain fluid balance • Globulins – 36% ~ Lipid transport and immune support • Fibrinogens – 4% ~ Blood clotting

6. Composition of Blood • Nitrogen-Containing Molecules • Amino Acids – transported to cells that need • Urea – excreted • Uric Acid – excreted • Nutrients and Gases • Glucose, fatty acids • O2 and CO2 • Electrolytes • Na+, K+, Ca++, Cl-, HCO3-, PO4-3

7. Formed Elements – 45% (hematocrit) – packed cell volume (PCV) • Cells and cell fragments • Hematopoiesis • Production of blood cells • After birth, occurs in red bone marrow and lymphoid tissue • Hemocytoblast • Stem cell that is the precursor to all formed elements

8. Erythrocytes (RBC) 4.5-6million/mm3 • Most numerous • Biconcave disks • Thin in middle, thick around periphery • Allows for flexibility and maximum surface area • Anucleate – What does this mean? • Cannot undergo mitosis –why? • How do we make new RBC’S? • Function • Transport O2 and CO2 • Uses hemoglobin

9. Lifecycle Fig. 11-3 • Production regulated by erythropoietin (hormone from liver) • Activated by renal erythropoietic factor (REF) from kidneys • Iron, vitamin B12 , folic acid are essential to RBC production

10. Live for about 120 days • Age  membrane elasticity and becomes fragile -> similar to our skin as we age • Macrophages (phagocytic) remove cells from circulation • 2 million destroyed and replaced every second! • Hemoglobin is separated into • Heme - Iron- recycled • Bilirubin – becomes part of bile & carried to sm. intestine

11. Leukocytes (WBC’s) 5,000 – 9,000/ mm3 • Larger and fewer than RBC’s • Derived from hemocytoblast stem cells • Do not lose nucleus • Do not have hemoglobin (appear white) • Most of the work takes place in tissues • Diapedesis • Process by which WBC’s move through capillary walls into tissue spaces

12. 2 main groups • Granulocytes • Cells that develop granuoles in cytoplasm • 3 types • Neutrophils – granules stain pink • Most common – 60-70% • First to respond to tissue damage • Engulf bacteria by phagocytosis •  # in acute infections – what is that?

13. Eosinophils – granules stain red • 2-4% • neutralize histamine • # during allergic reactions • destroy parasitic worms • Basophils – granules stain blue • <1% • those that enter tissue are called mast cells • secretes histamine - dilates blood vessels • secretes heparin - inhibits blood clot formation

14. Agranulocytes • Cells that do not have granules • 2 types • Lymphocytes • 20-25% • help fight against disease • T-cells –attack bacteria & viruses • B-cells- antibodies to bact. & tox

15. Monocytes • 3-8% • largest in size • when enter tissue called macrophages • engulf bacteria & cellular debris - finish cleanup started by neutrophils

16. Thrombocytes • Platelets • Not complete cells, fragments of megakaryocytes • Develop from hemocytoblasts • 250,000 – 500,000/mm3 • sticky & clump together to form platelet plugs • initiate blood clots

17. Hemostasis • stoppage of bleeding • 3 separate but interrelated processes • Vascular Constriction • First response to blood vessel injury • Contraction of smooth muscle in vessel walls • Restricts blood flow • Serotonin is released by platelets -> stimulates smooth muscle contract

18. Platelet Plug Formation • Platelets stick to collagen fibers exposed from torn connective tissue • Creates a mass of platelets, which obstructs the tear • Numerous tears daily

19. Coagulation • Formation of a blood clot • Procoagulants -> found in blood - Promote clotting • Anticoagulants - Inhibit clotting • 3 main steps (Fig. 11-5) • Platelets & damaged tissues release chemicals -> formation of prothrombin activator • Ca++ and prothrombin activator converts prothrombin to thrombin • Thrombin + Ca++ converts fibrinogen to fibrin -> forms a mesh that adheres to tissue & traps blood cells and platelets

20. Ca++, Vitamin K, platelets are necessary • After, fibrin strands contract • Pulls edges of wound together • Fibrinolysis • Dissolve of clot

21. Blood Typing and Transfusions • Transfusion • Transfer of blood, plasma, or other solution into the blood of another individual -> in the past were unsuccessful • Antigen • Molecules, usually proteins, that elicit a response from antibodies • Antibodies • Protein molecules that are produced in response to a foreign antigen • Very specific

22. Blood types are based on specific antigens and antibodies related to RBC’s • Agglutinogens • Antigens found on the cell membrane of erythrocytes • Agglutinins • Antibodies found in plasma • Agglutination • When agglutinins in plasma combine w/ agglutinogens on the surface of RBC’s • Causes clumping of RBC’s

23. ABO Blood Groups • Based on the presence or absence of certain agglutinogens • A + B • Type A -> A agglutinogens on cell membrane • Type B -> B “ “ • Type AB -> A and B “ “ • Type O -> neither A nor B “ “ • Agglutinins develop in plasma shortly after birth • Type A agglutinogens -> anti-B agglutinins • Type B agglutinogens -> anti-A agglutinins • Type AB agglutinogens -> neither agglutinin • Type O agglutinogens -> both anti-A and anti-Bagglutinins

24. Donor – gives blood • Recipient – receives blood • Agglutinins in plasma of recipient must NOT react w/ cells of donor blood

25. O = universal donor AB = universal recipient

26. Rh Blood Groups • Rh+ -> Rh agglutinogens on surface of RBC’s – 85% of pop. • Rh- -> no Rh agglutinogens • Normally, no anti-Rh agglutinins • If Rh- person exposed to Rh+ blood (transfusion, mother and fetus), the Rh- person develops Rh+ agglutinins • If exposed to Rh+ a second time -> a transfusion reaction results