TEST 3

• Functions of blood


  1. Transport of gases, nutrients and waste products

  - Oxygen, CO2, glucose, amino acids, fatty acids, metabolic end products

  
  

  2. Transport of processed molecules

  - Vitamin D precursor from skin to liver and kidneys

  
  

  3. Transport of regulatory molecules

  - Hormones (from endocrine glands to rest of body)

  
  

  4. Regulation of pH and osmosis

  - Normal pH between 7.35 and 7.45

  - Maintaining osmosis within body

  § Blood plays a huge role in maintaining fluid balance

  
  

  5. Maintenance of body temperature

  - Eg. Heat transfer from muscle tissue to blood to skin to external environment during exercise

  
  

  6. Protection against foreign substances

  - Antibodies produced

  - Response to infection

  
  

  7. Clot formation

  - "built-in" mechanism for self-repair of damaged tissues
• What composition of blood is the body made of?

  8% of total body weight

  - 4-6L in adults
• Composition and percentage of plasma

  plasma: 55%

  - proteins (7%)

  - water (91.5%)

  - other solutes (1.5%)
• Composition of proteins in plasma

  Albumins (58%)

  Globulins (38%)

  Fibrinogen (7%)

  All others (1%)
• Elements and materials that are found in "other solutes"

  Electrolytes

  nutrients

  gases

  regulatory substances

  water products
• What are formed elements?

  They are cell components because not all of them are full cells, some are fragments (platelets)
• What percentage of formed elements is found within RBC?

  45%
• Composition of formed elements

  - Platelets (150,000-400,000)

  - White blood cells (5000-10,000)

  - Red blood cells (4.8-5.4 million)
• Composition of white blood cells

  Neutrophils (60-70%)

  Lymphocytes (20-25%)

  Monocytes (3-8%)

  Eosinophils (2-4%)

  Basophils (0.5-1.0%)
• What is the liquid part of blood called?

  Plasma
• What is the fluid colloid?

  Contains suspended substances (evenly distributed throughout the fluid)
• Purpose of Albumins


  Most abundant (58%)

  - osmotic pressure, transports fatty acids, bilirubin, thyroid hormones

  - gets stuck inside our blood, maintains osmotic pressure
• Purpose of Globulins


  38% of plasma proteins

  - antibodies, transports lipids, iron, hormones
• Purpose of Fibrinogen


  4% of plasma proteins

  - blood clotting
• Structure and purpose of red blood cells (erythrocytes)

  - biconcave discs, no nucleus or mitochondria

  - contain hemoglobin (protein) transports oxygen and carbon dioxide

  - converts CO2 and H2O to carbonic acid (H2CO3): carbonic anhydrase
• 2 types of white blood cells (leukocytes)

  1. Granulocytes: large granules; have multi-lobed nuclei

  - neutrophils, eosinophils, basophils

  
  

  2. Agranulocytes: small granules and nuclei that are not lobed

  - lymphocytes and monocytes
• What are platelets and its functions?

  - cell fragment

  - form platelet plugs

  - release chemicals necessary for blood clotting
• Definition of hematopoiesis or hemopoiesis

  Process of blood cell production
• Post-birth


  Red bone marrow, lymphatic system
• Where are all formed elements derived from?

  They are derived from a single population (hemocytoblast)
• Proerythroblasts become...


  RBCs
• Myeloblasts become...


  Basophils, neutrophils, eosinophils
• Lymphoblasts become...


  lymphocytes
• Monoblasts become...


  monocytes
• Megakaryoblasts become...


  platelets
• How many RBCs are in adults?

  5.4 million/microlitre (men)

  4.8 million/microlitre (adult women)
• Components of RBCs


  1/3 hemoglobin, 2/3 lipids, ATP, carbonic anhydrase
• Transport functions of RBCs

  oxygen: 98.5% bound to hemoglobin; 1.5% dissolved in plasma

  
  

  carbon dioxide: 23% bound to hemoglobin (7% dissolved in plasma, 70% as bicarbonate)

  
  

  H+ : generated from carbonic anhydrase (CA) reaction
• Structure of hemoglobin


  4 globin molecules (polypeptide chains)

  - 4 heme molecules, each containing one iron atom

  - transport oxygen

  - transport carbon dioxide (CA involved)
• oxyhemoglobin vs deoxyhemoglobin


  Transporting oxygen vs no oxygen bound
• Carbaminohemoglobin


  Transporting CO2
• Erythropoiesis


  - Production of RBCs

  - takes approx 4 days

  - 2 million RBCs degenerate per second

  - 25 trillion RBCs in circulation

  - RBCs last 120 days in circulation
• What is the hormone that stimulates RBC production and where is it produced?

  Erythropoietin
• Functions and structure of white blood cells (leukocytes)

  - protect body against microorganisms and remove dead cells and debris

  - nucleated with no hemoglobin
• Movements of WBC


  - ameboid movement

  - diapedesis (emigration)

  - chemotaxis
• Ameboid movement


  where the plasma membrane of the cell create arm like extensions which wraps around debris and produce phagocytic actions
• Diapedesis (emigration)


  - cells become thin, elongate and move either between or through endothelial cells of capillaries

  - WBC's leave the CV system and enters tissues that surround the blood supply
• Chemotaxis


  - foreign materials release a chemical and the chemical attracts the WBC to the foreign material

  - attraction to and movement toward foreign materials or damaged cells (WBC will then sort of phagocytize those cells then die off)

  - accumulation of dead WBCs and bacteria is pus
• % component of Neutrophils in WBC and characteristics

  60-70% of WBC

  
  

  nuclei are lobed: 2-5 lobes

  
  

  10-12 hours in circulation, 1-2 days in tissues (produce these frequently)

  
  

  phagocytize bacteria/foreign matter (first line of defense)

  
  

  secrete lysozyme (enzymes metabolize bacteria)
• % component of Eosinophils in WBC and characteristics

  2-4% of WBC

  
  

  nuclei often have 2 lobes

  
  

  active in allergic reactions

  
  

  destroy inflammatory chemicals like histamine

  - limit response

  - reduces inflammation

  
  

  release chemicals that help destroy tapeworms, flukes, pinworms and hookworms