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Agenda Chapter 19: Blood –Major functions –Major Components –Structure of RBCs and WBCs –ABO Blood Types, and Rh Factor Lab 34.1 and “Blood Typing”

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Presentation on theme: "Agenda Chapter 19: Blood –Major functions –Major Components –Structure of RBCs and WBCs –ABO Blood Types, and Rh Factor Lab 34.1 and “Blood Typing”"— Presentation transcript:

1 Agenda Chapter 19: Blood –Major functions –Major Components –Structure of RBCs and WBCs –ABO Blood Types, and Rh Factor Lab 34.1 and “Blood Typing”

2 Blood: General functions Transport of dissolved gases, nutrients, hormones, and metabolic wastes Regulation of pH, ion composition of interstitial fluids Restriction of fluid loss at injury site Defense against toxins and pathogens Regulation of body temperature

3 Blood is Fluid Connective Tissue Recall that connective tissues are comprised of: specialized cells, extracellular protein fibers and fluid (ground substance) Matrix is a combo of the non-celluar components The matrix of blood is called plasma

4 Components of blood Plasma ~ 90% water ~ 10% dissolved (soluble) proteins most made by the liver Formed elements (cells and cell fragments) 1. RBCs 2. WBCs 3. Platelets

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7 Plasma proteins Albumins (60%) -major component of osmotic pressure of plasma Globulins (35%) -antibodies and transport proteins Fibrinogens (4%) -functions in blood clotting

8 Formed Elements: Hematocrit Percent of blood volume contributed to formed elements (cells) Centrifuge: separate components by density

9 Hematocrit Males ~ 46, Females ~ 42 What can effect hematocrit? –  : Dehydration and EPO (erythropoietin), testosterone –  : Internal bleeding, or defect in RBC formation

10 When you look at a smear of blood, which cells predominate??

11 20  m

12 RBCs Characteristics Function primarily to carry oxygen and CO 2 -contain hemoglobin (33% of cell weight) Lack a nucleus Contain few organelles (no mitochondria) –Can they generate ATP?? Make new protein? Shaped like biconcave discs -increases surface area for gas exchange Life span approx. 120 days FYI: 1  L of blood = ~ 5 million RBCs 1 drop of blood = ~ 260 million RBCs

13 Red Blood Cells  m ~ 0.8  m ~ 2.6  m Increased surface area, stackable, and flexible (can fit through 4  m capillaries)

14 Hemoglobin Composed of globin (protein) and pigment (heme) -Protein portion: 2  and 2  chains -Four heme units: contain iron and bind oxygen

15 Hemoglobin Quaternary Structure

16 Hematopoiesis Rate of RBC production controlled by erythropoietin (EPO) EPO produced by kidneys (upon exposure to low O 2 ) EPO acts on stem cells of red bone marrow, and  rate of maturation What is necessary for healthy RBCs? Myeloid stem cell

17 Fate of RBCs Life span of days In 1 min: travel from periphery, are squeezed through capillaries, sent to heart and back! Become trapped in the spleen (eaten by macrophage) -heme degraded to biliverdin (green) -biliverdin converted to bilirubin (orange-yellow) -bilirubin binds to albumin, transported to liver for excretion in BILE At large intestine, bacteria convert bilirubin to urobilinogens and stercobilinogens urobilins and stercobilins

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19 ABO Blood Types ABO system refers to the presence of surface antigens on the RBCs AND the antibodies in the plasma Antigens also called agglutinogens Antibodies called agglutinins

20 ABO Blood Types For a person with type A blood, the A antigens (surface proteins) inform the body’s defense system that “A” is “self”. For a persone with type A blood, which antigen(s) would alert the body as “non-self” or foreign? Type AType BType ABType O

21 ABO Blood Types When the body encounters “foreign” material, it generates antibodies against the surface antigens. When foreign RBC antigens are covered with antibodies, they clump and lyse (agglutination and hemolysis). What antibodies will each blood type have in the plasma? Type AType BType ABType O

22 Blood Types

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24 Rh Factor and Hemolytic Disease of the Newborn

25 Fetal cells enter mother’s circulation

26 Second pregnancy is attacked by maternal antibodies

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28 White Blood Cells (Leukocytes) Complete cells with nuclei and all organelles Fewer than RBCs ( /ul) Critical to the body’s defense (immune system) Special features - Can migrate out of bloodstream - Capable of amoeboid movement -Atracted to specific chemical stimuli (respond by positive chemotaxis) -Capable of phagocytosis (Neutrophils, Eosinophils, Monocytes)

29 Types of WBCs Neutrophils Eosinophils Basophils Monocytes Lymphocytes granulocytes agranulocytes Note that many of these cells have names that reflect the way these cells look when under the scope, when stained with certain dyes

30 Neutrophils Account for 50-70% of circulating WBCs Dense segmented nucleus with 2-5 lobes Highly mobile, often the ‘first to arrive on the scene’following injury Attack bacteria coated with antibodies While active, release prostaglandins and leukotrienes

31 Eosinophil 2-4% of WBCs Stain red, 2 lobed nucleus Attack cells coated with antibodies Importantly, protect against parasites via exocytosis of toxic compounds

32 Basophils Less than 1% Granules contain histamine, heparin Release enhances inflammation

33 Monocytes 2-8% of WBCs Remains in blood for 24hr before becoming a macrophage in tissue Macrophage=aggressive phagocytes While active, secrete chemicals that attract/stimulate other WBCs Also secrete chemicals that attract fibroblasts into region

34 Lymphocytes 20-30% of WBCs Note the round nucleus, little cytoplasm Most lymphocytes reside in connective tissue or lymphatic organs In circulating blood: B cells, T cells, and NK cells

35 WBC Production

36 Platelets Anuclear cell fragments, contain cytoplasm and proteins (4  m diameter) “Pinched off” from megakaryocytes in bone marrow Major participant in clotting response

37 Hemostasis Highly regulated process of halting blood loss 3 phases 1.Vascular phase 2.Platelet phase 3.Coagulation phase

38 Hemostasis: Vascular phase Cutting triggers smooth muscle contraction of vessel wall Basal lamina exposed to bloodstream Endothelial cells release chemical factors, local hormones --ADP, endothelins Endothelial cell membranes become ‘sticky’ --Platelets stick! Release of ADP and endothelins

39 Hemostasis: Platelet phase

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41 Hemostasis: Coagulation phase Fibrin is insoluble!


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