Circulatory

• Circulatory system


  All the routes in which different forms of circulatory fluids in our body would flow
• Blood


  Specialized body fluid
• Blood


  • Denser and more viscous than water
  • Thicker and slightly sticky
  • Temperature of 30 degrees Celsius
  • Slightly alkaline pH ranging from 7.35 to 7.45
  • Color depends on oxygen content
• Bright red blood


  Saturated with oxygen
• Dark red blood


  Unsaturated with oxygen
• Blood volume


  • 20% of extracellular fluid, 8% of total body mass
  • 5 to 6 liters or 1.5 gallons in an average adult male
  • 4 to 5 liters in an average size adult female
• Difference in blood volume between males and females


  Due to difference in body size
• Functions of blood


  • Transportation of oxygen and nutrients
  • Carries nutrients from GI tract to body cells
  • Transports heat and waste products
  • Blood clot formation
  • Carrier of antibodies
  • Carrier of waste products
  • Balance of acid-base, fluid, electrolytes, and temperature

  
• Whole blood


  Has two components: blood plasma and formed elements

  
• Platelets


  150,000 to 400,000 per cubic millimeter, responsible for blood clotting
• White blood cells


  3,500 to 9,100 per cubic millimeter, responsible for immunity

  
• Red blood cells


  4.0 to 5.6 million per cubic millimeter, responsible for oxygen transport
• Plasma


  91.5% water, 8.5% solutes including proteins, nutrients, hormones, waste products, gases, and regulatory substances

  
• Centrifugation


  Mechanical process using centrifugal force to separate particles from a solution based on size, density, medium viscosity, and rotor speed
• Centrifugation of blood


  Separates into plasma (55%), buffy coat (less than 1% leukocytes and platelets), and erythrocytes (45%)

  
• Formed elements of blood


  • Platelets
  • Red blood cells
  • White blood cells

  
• Platelets


  Cytoplasmic fragments of megakaryocytes, 150,000-400,000 per cubic millimeter
• Coagulation/clotting time


  Time required to form a clot, normally 8 to 15 minutes

  
• Bleeding time


  Time for blood vessel constriction and platelet plug formation, normally 2 to 7 minutes
• Prothrombin time


  Time for blood to form a clot, normally 11 to 13.5 seconds
• INR (International Normalized Ratio)


  Calculation based on prothrombin time test result, normal range 0.8 to 1.1
• PTT (Partial Thromboplastin Time)

  Normally 60 to 70 seconds
• aPTT (Activated Partial Thromboplastin Time)


  Monitors effectiveness of anticoagulation, normally 30 to 40 seconds
• Heparin

  Blood thinner, anticoagulant
• Prothrombin


  Made in the liver, converted to thrombin to stop bleeding
• Fibrinogen (soluble)


  Converted to fibrin (insoluble) during coagulation
• Leukocytes (WBCs)


  • Granulocytes (neutrophils, eosinophils, basophils)
  • Agranulocytes (lymphocytes, monocytes)

  
• Granulocytes


  • Most numerous WBCs, have granules and multilobed nuclei, larger than RBCs, responsible for inflammatory response

  
• Agranulocytes


  • For adaptive immunity, do not contain granules, have clear cytoplasm and visible nuclei, use immunologic memory

  
• Lymphocytes


  Classified by cell diameter as large (10-14 μm) or small (6-9 μm), increase in large lymphocytes indicates viral infection or immune deficiency

  
• Monocytes


  Kidney-shaped with blue-gray foamy cytoplasm, enlarge and differentiate into macrophages in tissues

  
• Erythrocytes (RBCs)


  • Majority of blood cells, 7.7 μm diameter, contain hemoglobin for oxygen transport, lack mitochondria and generate ATP anaerobically, biconcave shape aids function

  
• Hemoglobin transports 23% of total carbon dioxide as a waste product of metabolism, the remaining 77% is dissolved in plasma or carried as bicarbonate ion
• Hemoglobin


  Composed of a protein "globin" and a non-protein pigment "heme", plays a role in regulating blood flow and pressure by releasing nitric oxide
• Erythropoiesis


  Production of red blood cells in bone marrow, liver, spleen, and fetal bone marrow

  
• Plasma


  Serum is the clear portion with fibrinogen clotting factor removed
• Plasma (other solutes)


  Includes ions, nutrients, waste products, gases, and regulatory substances
• ABO blood group


  Based on A and B glycolipid antigens on red blood cells
• Rh blood group


  Based on presence or absence of Rh antigen, people with Rh antigen are Rh positive, those without are Rh negative
• People with type AB blood are universal recipients, those with type O blood are universal donors