blood

• Hematopoiesis


  A continuous, regulated process of blood cell production that includes cell renewal, proliferation, differentiation and maturation

  
• Hypoxia stimulates RBC production
• Erythropoietin (EPO)


  A hormone glycoprotein produced in the kidney and liver that stimulates the production of globin and enhances the release of reticulocytes in circulation
• Functions of blood


  • Transports of gases, nutrients and waste products
  • Transports of processed and regulatory molecules
  • Regulation of pH and osmosis
  • Maintenance of body temperature
  • Protection against foreign substance
  • Clot formation
• General characteristics of blood

  • In vivo, blood is in fluid form; In vitro, it coagulates 5-10 minutes
  • Thick and viscous; 3.5-4.5 times thicker than water
  • Approximately 20 grams solid per 100 ml blood
  • Blood pH: 7.35-7.45 (average: 7.40)
  • Color: Arterial Blood- BRIGHT RED, Venous Blood- DARK Red

  
• Plasma


  Fluid portion of anticoagulated blood

  
• Serum


  Fluid portion of non-anticoagulated blood
• Blood film well stained with Wright’s stain have a pink to purple color when viewed with the naked eye

  
• Normal values for Red Blood Cell count

  • Male: 4.20 – 6.00 x1012/L
  • Female: 3.80 – 5.20 X1012/L

  
• Normal values for Hemoglobin count

  • Male: 13.5-18 g/dl
  • Female: 12-15 g/dl
• Normal values for Hematocrit

  • Male: 40-to 54%
  • Female: 35-49%
• Normal values for White Blood Cell count

  • Male: 4.0 – 11.0 X10 12/L

  
• Normal values for Platelet count

  • 150-400 x1012/L
• Differential count reference intervals

  • Neutrophils: 50-70%
  • Lymphocytes: 18-42%
  • Monocytes: 2-11%
  • Eosinophils: 1-4%
  • Basophils: 0-1%
• Hematopoietic Stem Cells retain the ability to differentiate into any cell lines
• Progenitor Cells


  Differentiate into only one cell line
• Precursor Cells


  Blasts forms including myeloblast, megakaryoblast, erythroblast
• Red/Active Marrow


  • Developing blood cells and their progenitors
• Yellow/Inactive Marrow


  • Composed primarily of adipocytes
• Retrogression is the process of replacing the active marrow by adipocytes during development
• Red Blood Cells


  Biconcave discs, one-third hemoglobin, able to readily squeeze through capillaries, lack nuclei and cytoplasmic organelles, normal concentration of erythrocytes in blood is approximately 3.9-5.5 million/uL in women and 4.1-6 million/uL in men

  
• RBC development


  1. Takes about 7 days and is called erythropoiesis

  2. Pass through several stages of development before entering the blood
• Red Blood Cell Maturation Series (The Precursors)

  • Pronormoblast
  • Basophilic normoblast
  • Polychromatophilic normoblast
  • Orthochromatic normoblast
  • Reticulocyte
  • Mature erythrocyte

  
• Hemoglobin


  The main component of a red blood cell responsible for transport of O2 from lungs to tissues and CO2 from tissues to lungs
• Hemoglobin accounts for about a third of the cell’s volume
• Types of Hemoglobin


  • Fetal Hemoglobin (HB F)
  • Adult Hemoglobin (HB A)
• Anemia is defined as a DECREASE in RBC, Hb, and hematocrit resulting in decreased oxygen delivery to the tissues
• Iron Deficiency Anemia/Nutritional Anemia


  • Most common form of anemia
  • Prevalent in infants and children
  • Pregnancy
  • Excessive menstrual flow
  • Elderly
• Heme is converted into bilirubin.
• Iron is transported in the blood to the red bone marrow and used in the production of new hemoglobin.
• The globin chains of hemoglobin are broken down to individual amino acids and are metabolized or used to build new proteins.
• Bilirubin is transported in the blood to the liver.
• Bilirubin is excreted as part of the bile into the small intestine.
• Some bilirubin derivatives contribute to the color of feces.
• Other bilirubin derivatives are reabsorbed from the intestine into the blood and excreted from the kidneys in the urine, contributing to the color of urine.
• Anemia


  A DECREASE in RBC, Hb, and hematocrit resulting in decreased oxygen delivery to the tissues.
• Classification of anemias


  • Classified morphologically using RBC indices
  • Classified based on etiology/cause
• Iron deficiency anemia is the most common form of anemia.
• Prevalence of iron deficiency anemia

  • Infants
  • Children
  • Pregnancy
  • Excessive menstrual flow
  • Elderly with poor diets
  • Malabsorption syndromes
  • Chronic blood loss
• Etiology of iron deficiency anemia

  • Inadequate intake of iron
  • Increased demand (Pregnancy, Infancy and childhood)
  • Impaired iron absorption (Celiac disease and decrease stomach acidity)
  • Chronic blood loss