1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 14 Lecture PowerPoint

2 14.1: Introduction Blood: Is connective tissue Transports vital substances Maintains stability of interstitial fluid Distributes heat Blood cells: Form mostly in red bone marrow and are: Red blood cells (RBCs) White blood cells (WBCs) Platelets (cell fragments) The amount of blood varies with body size, changes in fluid concentration, changes in electrolyte concentration, and amount of adipose tissue Blood is about 8% of body weight Adult blood volume is about 5 liters

3 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Centrifuged Blood Sample Peripheral Blood Smear Liquid (plasma) “Buffy coat” (white blood cells and platelets) Red blood cells Platelets White blood cells

4 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Plasma = 55% Capillary tube Plug Buffy coat Red cells = 45% (hematocrit)

5 Blood (4.8%)(95.1%)(0.1%) Plasma Hormones MonocytesBasophilsEosinophilsNeutrophils (54–62%)(1–3%)(<1%)(3–9%)(25–33%) GlobulinsAlbumins (92%)(7%) N2N2 O2O2 CO 2 PlateletsRed blood cells ProteinsNutrientsGases 45%55% WastesWater White blood cellsElectrolytes Vitamins LymphocytesFibrinogen Formed elements Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

6 14.2: Blood Cells Blood cells originate in red marrow from hemocytoblasts or hematopoietic stem cells Stem cells can then: Give rise to more stem cells Specialize or differentiate

7 The Origin of Blood Cells Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (b) Megakaryoblast Myeloid stem cell Megakaryocyte Monocyte Macrophage T lymphocyte B lymphocyte Plasma cell Hematopoietic stem cell Myeloblast Progranulocyte Erythroblast Normoblast Reticulocyte Erythrocyte In circulating blood Neutrophil Basophil Granulocytes Eosinophil Proerythroblast Monoblast Promonocyte Prolymphocyte In red bone marrow Agranulocytes (a) Lymphoid stem cell Lymphoblast B cell precursor Lymphoblast T cell precursor Neutrophilic myelocyte Basophilic myelocyte Eosinophilic myelocyte Eosinophilic band cell Basophilic band cell Neutrophilic band cell Thrombocytes (platelets) Activated in tissues (some cells)

8 Characteristics of Red Blood Cells Red blood cells are: Erythrocytes Biconcave discs One-third hemoglobin or: Oxyhemoglobin Deoxyhemoglobin Able to readily squeeze through capillaries Lack nuclei and mitochondria Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Top view 2.0 micrometers 7.5 micrometers Sectional view (a) (b) b: © Bill Longcore/Photo Researchers, Inc.

9 Red Blood Cell Counts RBC counts is the number of RBCs in a cubic millimeter or microliter of blood It may vary depending on age and health Typical ranges include: 4,600,000 – 6,200,000 in males 4,200,000 – 5,400,000 in adult females 4,500,000 – 5,100,000 in children RBC counts reflects blood’s oxygen carrying capacity

10 Red Blood Cell Production and Its Control Low blood oxygen causes the kidneys and the liver to release erythropoietin (EPO) which stimulates RBC production This is a negative feedback mechanism Within a few days many new blood cells appear in the circulating blood Low blood oxygen LiverKidney Erythropoietin Red bone marrow + – Bloodstream Stimulation Inhibition Release into bloodstream Increased oxygen- carrying capacity Increased number of red blood cells Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

11 Dietary Factors Affecting Red Blood Cell Production Vitamin B 12 and folic acid are necessary They are required for DNA synthesis making them necessary for the growth and division of all cells Iron is also necessary It is required for hemoglobin synthesis

12 Bilirubin Bone Blood Liver Globin + Heme 3 2 1Absorption 4 5 Macrophage Hemoglobin Iron + Biliverdin Bile Red bone marrow Red blood cells produced Red blood cells circulate in bloodstream for about 120 days Old red blood cells Blood transports absorbed nutrients Nutrients from food Vitamin B 12 Folic acid Iron Small intestine Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

(b) (a) a: © The McGraw-Hill Companies, Inc./Al Telser, photographer :b © Ed Reschke Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 13

14 Destruction of Red Blood Cells

15 Types of White Blood Cells White blood cells: Are leukocytes Protect against disease WBC hormones are interleukins and colony-stimulating factors which stimulate development There are five types of WBCs in two categories: Granulocytes Neutrophils Eosinophils Basophils Agranulocytes Lymphocytes Monocytes

16 Neutrophils Light purple granules in acid-base stain Lobed nucleus Other names Segs Polymorphonuclear leukocyte Bands (young neutrophils) First to arrive at infections Phagocytic 54% - 62% of leukocytes Elevated in bacterial infections © Ed Reschke Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

17 Eosinophils Deep red granules in acid stain Bi-lobed nucleus Moderate allergic reactions Defend against parasitic worm infestations 1% - 3% of leukocytes Elevated in parasitic worm infestations and allergic reactions © Ed Reschke Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

18 Basophils Deep blue granules in basic stain Release histamine Release heparin Less than 1% of leukocytes Similar to eosinophils in size and shape of nuclei © Ed Reschke Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

19 Monocytes Largest of all blood cells Spherical, kidney-shaped, oval or lobed nuclei Leave bloodstream to become macrophages 3% - 9% of leukocytes Phagocytize bacteria, dead cells, and other debris © R. Kessel/Visuals Unlimited Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

20 Lymphocytes Slightly larger than RBC Large spherical nucleus surrounded by thin rim of cytoplasm T cells and B cells Both important in immunity B cells produce antibodies 25% - 33% of leukocytes © Ed Reschke Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

21 Functions of White Blood Cells WBCs protect against infection These leukocytes can squeeze between the cells of a capillary wall and enter the tissue space outside the blood vessel (called diapedesis) Blood capillary Leukocyte Connective tissue Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

22 Epidermis Dermis Blood vessels 1 Splinter punctures epidermis Injured cells release histamine, causing blood vessels to dilate Bacteria multiply Bacteria are introduced into the dermis Neutrophils destroy bacteria by phagocytosis Neutrophils move through blood vessel walls and migrate toward bacteria Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

23 White Blood Cell Counts A procedure used to count number of WBCs per cubic millimeter of blood Typically 5,000 – 10,000 per cubic millimeter of blood Leukopenia: Low WBC count (below 5,000) Typhoid fever, flu, measles, mumps, chicken pox, AIDS Leukocytosis: High WBC count (above 10,000) Acute infections, vigorous exercise, great loss of body fluids Differential WBC count Lists percentages of types of leukocytes May change in particular diseases

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25 Blood Platelets Platelets are also known as thrombocytes They are cell fragments of megakaryocytes They lack a nucleus and are roughly half the size of a RBC There are approximately 130,000 – 360,000 per cubic millimeter of blood They help repair damaged blood vessels by sticking to broken surfaces

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: Blood Plasma Blood plasma is: Straw colored The liquid portion of blood 55% of blood volume 92% water Includes transporting nutrients, gases, and vitamins Helps regulate fluid and electrolyte balance and maintain pH

28 Plasma Proteins These are the most abundant dissolved substances (solutes) in plasma

29 Gases and Nutrients The most important blood gases: Oxygen Carbon dioxide Plasma nutrients include: Amino acids Simple sugars Nucleotides Lipids Fats (triglycerides) Phospholipids Cholesterol

30 Nonprotein Nitrogenous Substances These are molecules containing nitrogen but are not proteins In plasma they include: Urea – product of protein catabolism; about 50% of nonprotein nitrogenous substances Uric acid – product of nucleic acid catabolism Amino acids – product of protein catabolism Creatine – stores phosphates Creatinine – product of creatine metabolism BUN – blood urea nitrogen; indicates health of kidney

31 Plasma Electrolytes Plasma contains a variety of these ions called electrolytes They are absorbed from the intestine or released as by- products of cellular metabolism They include: Sodium (most abundant with chloride) Potassium Calcium Magnesium Chloride (most abundant with sodium) Bicarbonate Phosphate Sulfate