Chapter 18 *Lecture Powerpoint the Circulatory System: Blood

Chapter 18 *Lecture Powerpoint the Circulatory System: Blood

Chapter 18 *Lecture PowerPoint The Circulatory System: Blood *See separate FlexArt PowerPoint slides for all figures and tables preinserted into PowerPoint without notes. Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Introduction • Many myths about blood – Mysterious ―vital force‖ – Drained ―bad-blood‖ for medical reasons – Hereditary traits were once thought to be transmitted through blood • Blood cells were seen with the first microscopes • Hematology—the study of blood • Recent developments in this field help save lives 18-2 Introduction • Expected Learning Outcomes – Describe the functions and major components of the circulatory system. – Describe the components and physical properties of blood. – Describe the composition of blood plasma. – Explain the significance of blood viscosity and osmolarity. – Describe in general terms how blood is produced. 18-3 Functions of the Circulatory System • Circulatory system consists of the heart, blood vessels, and blood • Cardiovascular system refers only to the heart and blood vessels • Hematology—the study of blood • Functions of circulatory system – Transport • O2, CO2, nutrients, wastes, hormones, and stem cells – Protection • Inflammation, limit spread of infection, destroy microorganisms and cancer cells, neutralize toxins, and initiate clotting – Regulation • Fluid balance, stabilizes pH of ECF, and temperature control 18-4 Components and General Properties of Blood • Adults have 4 to 6 L of blood • A liquid connective tissue consisting of cells and extracellular matrix – Plasma: matrix of blood • Clear, light yellow fluid – Formed elements: blood cells and cell fragments • Red blood cells, white blood cells, and platelets 18-5 Components and General Properties of Blood • Seven kinds of formed elements – 1)Erythrocytes: red blood cells (RBCs) – 2)Platelets • Cell fragments from special cell in bone marrow – Leukocytes: white blood cells (WBCs) • Five leukocyte types divided into two categories • Granulocytes (with granules) – 3)Neutrophils – 4)Eosinophils – 5)Basophils • Agranulocytes (without granules) – 6)Lymphocytes – 7)Monocytes 18-6 Components and General Properties of Blood Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Monocyte Small lymphocyte Neutrophil Platelets Eosinophil Small Erythrocyte lymphocyte Young (band) neutrophil Neutrophil Monocyte Large lymphocyte Neutrophil Basophil Figure 18.1 18-7 Blood Plasma • Hematocrit—centrifuge blood to Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Withdraw separate components blood – Erythrocytes are heaviest and settle first • 37% to 52% total volume – White blood cells and platelets Centrifuge • 1% total volume • Buffy coat Plasma (55% of whole blood) – Plasma • The remainder of volume Buffy coat: leukocytes • 47% to 63% and platelets (<1% of whole blood) • Complex mixture of water, Erythrocytes Formed proteins, nutrients, (45% of whole blood) elements electrolytes, nitrogenous wastes, hormones, and gases 18-8 Figure 18.2 Blood Plasma • Plasma—liquid portion of blood – Serum: remaining fluid when blood clots and the solids are removed • Identical to plasma except for the absence of fibrinogen • Three major categories of plasma proteins – Albumins: smallest and most abundant • Contribute to viscosity and osmolarity; influence blood pressure, flow, and fluid balance – Globulins (antibodies) • Provide immune system functions • Alpha, beta, and gamma globulins – Fibrinogen • Precursor of fibrin threads that help form blood clots 18-9 Blood Plasma • Plasma proteins formed by liver – Except globulins (produced by plasma cells) • Nitrogenous compounds – Free amino acids • From dietary protein or tissue breakdown – Nitrogenous wastes (urea) • Toxic end products of catabolism • Normally removed by the kidneys 18-10 Blood Plasma • Nutrients – Glucose, vitamins, fats, cholesterol, phospholipids, and minerals • Dissolved O2, CO2, and nitrogen • Electrolytes – Na+ makes up 90% of plasma cations 18-11 Blood Viscosity and Osmolarity • Viscosity—resistance of a fluid to flow, resulting from the cohesion of its particles – Whole blood 4.5 to 5.5 times as viscous as water – Plasma is 2.0 times as viscous as water • Important in circulatory function 18-12 Blood Viscosity and Osmolarity • Osmolarity of blood—the total molarity of those dissolved particles that cannot pass through the blood vessel wall – If too high, blood absorbs too much water, increasing the blood pressure – If too low, too much water stays in tissue, blood pressure drops, and edema occurs – Optimum osmolarity is achieved by the body’s regulation of sodium ions, proteins, and red blood cells 18-13 Starvation and Plasma Protein Deficiency • Hypoproteinemia – Deficiency of plasma proteins • Extreme starvation • Liver or kidney disease • Severe burns • Kwashiorkor – Children with severe protein deficiency • Fed on cereals once weaned – Thin arms and legs – Swollen abdomen 18-14 How Blood Is Produced • Adult production of 400 billion platelets, 200 billion RBCs, and 10 billion WBCs every day • Hemopoiesis—production of blood, especially its formed elements • Hemopoietic tissues produce blood cells – Yolk sac produces stem cells for first blood cells • Colonize fetal bone marrow, liver, spleen, and thymus – Liver stops producing blood cells at birth – Spleen remains involved with lymphocyte production 18-15 How Blood is Produced – Red bone marrow produces all seven formed elements • Pluripotent stem cells (PPSC) – Formerly called hemocytoblasts or hemopoietic stem cells • Colony-forming units—specialized stem cells only producing one class of formed element of blood • Myeloid hemopoiesis—blood formation in the bone marrow • Lymphoid hemopoiesis—blood formation in the lymphatic organs 18-16 Erythrocytes • Expected Learning Outcomes – Discuss the structure and function of erythrocytes (RBCs). – Describe the structure and function of hemoglobin. – State and define some clinical measurements of RBC and hemoglobin quantities. – Describe the life cycle of erythrocytes. – Name and describe the types, causes, and effects of RBC excesses and deficiencies. 18-17 Erythrocytes Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Capillary wall Erythrocytes Figure 18.4c (c) 7 µm © Dr. Don W. Fawcett/Visuals Unlimited • Two principal functions – Carry oxygen from lungs to cell tissues – Pick up CO2 from tissues and bring to lungs • Insufficient RBCs may kill in minutes due to lack of oxygen to tissues 18-18 Form and Function Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Disc-shaped cell with thick rim Surface view – 7.5 m diameter and 2.0 m thick at rim 7.5 µm – Lose nearly all organelles during development • Lack mitochondria – Anaerobic fermentation to produce ATP 2.0 µm • Lack of nucleus and DNA (a) Sectional view – No protein synthesis or mitosis Figure 18.4a 18-19 Form and Function – Blood type determined by surface glycoprotein and glycolipids – Cytoskeletal proteins (spectrin and actin) give membrane durability and resilience • Stretch and bend as squeezed through small capillaries 18-20 Form and Function • Gas transport—major function – Increased surface area/volume ratio • Due to loss of organelles during maturation • Increases diffusion rate of substances – 33% of cytoplasm is hemoglobin (Hb) • 280 million hemoglobin molecules on one RBC • O2 delivery to tissue and CO2 transport to lungs • Carbonic anhydrase (CAH) in cytoplasm – Produces carbonic acid from CO2 and water – Important role in gas transport and pH balance 18-21 Hemoglobin Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. • Each Hb molecule consists of: Beta Alpha – Four protein chains—globins Heme groups – Four heme groups (a) Alpha Beta CH3 CH CH2 • Heme groups C C HC C C CH – Nonprotein moiety that binds O2 C N C CH C CH 2+ 3 C 3 to ferrous ion (Fe ) at its center N Fe2+ N CH2 C C CH CH2 C N C CH 2 HC C C CH COOH C C CH2 CH3 CH2 COOH (b) Figure 18.5a,b 18-22 Hemoglobin • Globins—four protein chains – Two alpha and two beta chains – 5% CO2 in blood is bound to globin moiety • Adult vs. fetal hemoglobin 18-23 Quantities of Erythrocytes and Hemoglobin • RBC count and hemoglobin concentration indicate amount of O2 blood can carry – Hematocrit (packed cell volume): percentage of whole blood volume composed of RBCs • Men 42% to 52% cells; women 37% to 48% cells – Hemoglobin concentration of whole blood • Men 13 to 18 g/dL; women 12 to 16 g/dL – RBC count • Men 4.6 to 6.2 million/L; women 4.2 to 5.4 million/L 18-24 Quantities of Erythrocytes and Hemoglobin • Values are lower in women – Androgens stimulate RBC production – Women have periodic menstrual losses – Hematocrit is inversely proportional to percentage of body fat 18-25 Erythrocyte Production Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Pluripotent Colony-forming Precursor Mature stem cell unit (CFU) cells cell Erythrocyte CFU Erythroblast Reticulocyte Erythrocyte Figure 18.6 • 2.5 million RBCs are produced per second • Average lifespan of about 120 days • Development takes 3 to 5 days – Reduction in cell size, increase in cell number, synthesis of hemoglobin, and loss of nucleus 18-26 Erythrocyte Production Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Pluripotent Colony-forming Precursor Mature stem

View Full Text

Details

  • File Type
    pdf
  • Upload Time
    -
  • Content Languages
    English
  • Upload User
    Anonymous/Not logged-in
  • File Pages
    94 Page
  • File Size
    -

Download

Channel Download Status
Express Download Enable

Copyright

We respect the copyrights and intellectual property rights of all users. All uploaded documents are either original works of the uploader or authorized works of the rightful owners.

  • Not to be reproduced or distributed without explicit permission.
  • Not used for commercial purposes outside of approved use cases.
  • Not used to infringe on the rights of the original creators.
  • If you believe any content infringes your copyright, please contact us immediately.

Support

For help with questions, suggestions, or problems, please contact us