Chapter 14 Blood

1. Chapter 14Blood • Functions • transports vital substances • maintains stability of interstitial fluid • distributes heat • protection • regulation • Blood Cells • form mostly in red bone marrow • red blood cells/erythrocytes • white blood cells/leukocytes • platelets (cell fragments)/thromobocytes 14-2

2. Blood Volume • varies with • body size • changes in fluid concentration • changes in electrolyte concentration • amount of adipose tissue • about 8% of body weight • about 5 liters 14-3

3. Blood Composition 14-4

4. Origin of Blood Cells 14-5

6. Red Blood Cells • erythrocytes • biconcave • one-third hemoglobin • oxyhemoglobin • deoxyhemoglobin • can readily squeeze through • capillaries • lack nuclei and mitochondria 14-6

7. Hemoglobin Globin – protein Heme – pigment; iron Four globin molecules make up a hemoglobin; each carries 1 oxygen 1 RBC has approx. 250 million hemoglobin molecules

8. Red Blood Cell Count • number of RBCs in a cubic millimeter of blood • 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 • reflects blood’s oxygen carrying capacity 14-7

9. Red Blood Cell ProductionErythropoiesis • low blood oxygen causes kidneys and liver to release erythropoietin which stimulates RBC production • Erytrhopoietin is released when blood oxygen concentrations are low • vitamin B12, folic acid and iron necessary 14-8

10. Life Cycle of Red Blood Cell • circulate for about 120 days • macrophages in spleen and liver destroy worn out RBCs • hemoglobin is broken down into heme and globin • iron return to red bone marrow • bilirubin and biliverdin excreted in bile 14-9

11. MegakaryocytePlatelets

12. White Blood Cells • leukocytes • protect against disease • interleukins and colony-stimulating factors stimulate development • granulocytes • neutrophils • eosinophils • basophils • agranulocytes • lymphocytes • monocytes 14-12

13. Neutrophils • light blue granules in acid-base stain • lobed nucleus • first to arrive at infections • phagocytic: bacteria, fungi, some viruses • 54% - 62% of leukocyte • elevated in bacterial infections 14-13

14. Basophils • deep blue granules is basic stain • release histamine • release heparin • less than 1% of leukocytes 14-14

15. Eosinophils • deep red granules in acid stain • bilobed nucleus • moderate allergic reactions • defend against parasitic worm infestations • 1% - 3% of leukocytes • elevated in worm infestations and allergic reactions 14-15

16. Monocytes • largest blood cell • kidney-shaped or oval nuclei • leave bloodstream to become macrophages • Phagocyte : bacteria, dead cells, debris from injury/illness • 3% - 9% of leukocytes • elevated in typhoid fever, malaria, tuberculosis 14-16

17. Lymphocytes • about the size of RBC • large spherical nuclei; thin rims of cytoplasm • T cells – attack microorganisms, tumor cells, and transplanted cells • B cells – make antibodies (proteins that attack foreign invaders. • 25% - 33% of leukocytes • decreased T Cells in AIDS 14-17

18. Diapadesis • leukocytes squeeze through capillary walls to enter tissue space outside the blood vessel Pus – accumulation of bacteria, leukocytes, and damaged cells 14-18

19. White Blood Cell Counts • number of WBCs per cubic millimeter of blood • 5,000 – 10,000 per cubic millimeter of blood • leukopenia • low WBC count • typhoid fever, flu, measles, mumps, chicken pox, AIDS • leukocytosis • high WBC count • acute infections, vigorous exercise, great loss of body fluids • differential WBC count • lists percentages of types of leukocytes • may change in particular diseases 14-19

20. Blood Platelets • thrombocytes • cell fragments of megakaryocytes; anucleate • 130,000 – 360,000 per cubic millimeter of blood • helps control blood loss from broken vessels • Serotonin – reduce blood flow by constricting blood vessels • Thrombopoietin – hormone that stimulates platelet production 14-20

21. RBC Disorders Polycythemia -- Increased RBC – increased stamina and performance -- blood more viscous Causes – bone marrow cancer, high altitude, blood doping,

22. Anemia – lacking blood -- low oxygen carrying capacity -- fatigue, pale, short of breath • 3 Reasons • 1) low hematocrit • Causes – blood loss, excessive RBC destruction, bone marrow failure • Types – hemorrhagic, hemolytic, aplastic 2) Low Hemoglobin Content Types -- nutritional, iron-deficiency, Athlete’s, perniciuos 3) Abnormal Hemoglobin Types – thalassemia, sickle cell

23. WBC Disorders Leukopenia – low WBC count Leukemia -- white blood -- cancer of WBCs; named for cell type involved 2 Catogories Acute – usually in children Chronic – usually in elderly Symptoms – anemia, fever, wieight loss, bone pain Infectious Mononucleosis - viral infection -excessive agranulacytes Symptoms – tired, achy, chronic sore throatm low grade fever

24. Blood Plasma • straw colored • liquid portion of blood • 55% of blood • contains over 100 different dissolved solutes 14-21

25. Plasma Proteins • Albumins • most numerous plasma proteins • originate in liver • Carry molecules in plasma • help maintain osmotic pressure of blood • Alpha and Beta Globulins • originate in liver • transport lipids and fat-soluble vitamins • Fibrinogen • originate in liver • plays key role in blood coagulation • Gamma Globulins • originate in lymphatic tissues • constitute the antibodies of immunity 14-22

26. Plasma Lipoproteins Density is determined by amount of lipids and proteins • Chylomicrons • high concentration of triglycerides • transport dietary fats to muscles and adipose cells • VLDLs • relatively high concentration of triglycerides • produced in the liver • transport triglycerides from liver to adipose cells • LDLs • relatively high concentration of cholesterol • formed from VLDLs • deliver cholesterol to various cells • HDLs • relatively high concentration of proteins • relatively low concentration of lipids • transport remnants of chylomicrons to liver 14-24