Chapter 14 Blood Functions transports vital substances maintains stability of interstitial fluid distributes heat Blood Cells form mostly in red bone marrow red blood cells white blood cells platelets (cell fragments) 14-2

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

Blood Composition 14-4

Origin of Blood Cells 14-5

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

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

Red Blood Cell Production low blood oxygen causes kidneys and liver to release erythropoietin which stimulates RBC production vitamin B12, folic acid and iron necessary 14-8

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

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

Neutrophils light blue granules in acid-base stain lobed nucleus other names segs polymorphonuclear leukocyte bands (young neutrophils) first to arrive at infections phagocytic 54% - 62% of leukocyte elevated in bacterial infections 14-13

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

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

Monocytes largest blood cell kidney-shaped or oval nuclei leave bloodstream to become macrophages 3% - 9% of leukocytes elevated in typhoid fever, malaria, tuberculosis 14-16

Lymphocytes about the size of RBC large spherical nuclei thin rims of cytoplasm T cells B cells important in immunity produce antibodies 25% - 33% of leukocytes decreased T Cells in AIDS 14-17

Diapadesis leukocytes squeeze through capillary walls to enter tissue space outside the blood vessel 14-18

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

Blood Platelets thrombocytes cell fragments of megakaryocytes 130,000 – 360,000 per cubic millimeter of blood helps control blood loss from broken vessels 14-20

Blood Clots After forming, blood clot retracts and pulls the edges of a broken vessel together Platelet-derived growth factor stimulates smooth muscle cells and fibroblasts to repair damaged blood vessels Plasmin digests blood clots thrombus – abnormal blood clot embolus – blood clot moving through blood 14-31

Blood Plasma straw colored liquid portion of blood 55% of blood 14-21

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

Gases and Nutrients Nutrients Gases amino acids oxygen simple sugars nucleotides lipids lipoproteins Gases oxygen carbon dioxide nitrogen 14-23

ABO Blood Group 14-33

Agglutination 14-34

Preferred and Permissible Blood Types for Transfusion 14-35