VPHY 141 Finals

• Functions of Blood


  • Transports Substances to Different Parts of the Body
  • Maintains Internal Environment of Cells for Homeostasis
  • Regulates Temperature
  • Regulates Buffering System in the Body
  • Defends the Body against Invading Organisms
  • Serves as Carrier of Hemoglobin
  • Involve in the Clotting Mechanism (Platelets)

  
• Substances transported by blood

  • Hormones
  • Nutrients & digestion products
  • Cell metabolic waste products
  • O2 from lungs to cells of tissues
  • CO2 from cell tissues to lungs

  
• Blood is a very important fluid that are transported by the blood vessels throughout the body of the animal
• Blood as a transport medium is responsible for delivering substances needed by specific cells/tissues or for elimination

  
• Hemoglobin is a carrier of oxygen and carbon dioxide (gas attaches here)

  
• Platelets in mammals or also known as thrombocytes in avians are important in blood clotting to control bleeding
• Components of Blood


  • Plasma
  • Buffy coat area (white blood cells and platelets)
  • Red cell mass (packed cell volume, red blood cells)

  
• Whole blood contains 70% plasma and 30% cellular components

  
• Plasma


  Composed of water (majority) and other pertinent substances
• Serum


  Contains the water, minerals, ions, dissolved gases, hormones, substances such as glucose, amino acids, fats, and metabolic - urea, creatine, etc.
• Cellular components of blood

  • Red blood cells
  • Platelets
  • White blood cells

  
• Types of white blood cells

  • Granular leukocytes (neutrophils, basophils, eosinophils)
  • Agranular leukocytes (lymphocytes, monocyte)

  
• Parameters for gross examination of plasma

  • Color
  • Transparency
  • Presence or absence of blood
  • Presence or absence of sediments
• Protocols must be followed to prevent hemolysis when collecting blood
• Gross characteristics of plasma

  • Pale yellow, transparent (dog, cat, sheep, goat, cattle)
  • Dark yellow, transparent (horse)
• Physiologic factors that can influence the color of the plasma

  • Diet of animal
  • Strenuous activity
  • Hydration status
• Intense yellow plasma


  Icterus or jaundice - accumulation of bilirubin in mucous membranes and blood of animal

  
• Pale, colorless plasma


  Bone marrow depression, acute hemorrhage
• Cloudy plasma


  Lipemia (high blood cholesterol)

  
• Red-tinged plasma


  Hemolysis - can be caused by different invading organisms (viruses, bacteria, parasites) and mishandling during blood collection

  
• Components of plasma


  • Water
  • Plasma proteins
  • Electrolytes
  • Nutrients
  • Gases (oxygen, carbon dioxide)
  • Hormones
  • Metabolic waste
• Fibrinogen


  Responsible for blood clotting or hemostasis

  
• Oxygen diffuses from the lung's alveolus then will bind to the erythrocyte's hemoglobin or the red blood cells that will transport it to the specific tissue or cell where oxygen would detach from the hemoglobin and diffuse out of the cell to the capillary to the cell for oxygenation

  
• Carbon dioxide diffused to the RBC then to the lungs to be converted to oxygen
• Three main plasma proteins

  • Albumin
  • Fibrinogen
  • Globulins

  
• Types of globulins


  • α globulin
  • β globulin
  • γ globulin
• Granulocytes are the neutrophil, eosinophil, basophil
• Agranular cells are the monocyte and lymphocyte
• For mammalian species, we have fragments of the meta megakaryocyte called platelets
• Differences between mammalian and avian RBCs

  • Shape (biconcave disc vs oval)
  • Nucleus (absent vs present)
• Functions of RBC


  Transport of gases (CO2, O2)
• Hemoglobin is the respiratory pigment protein in RBCs

  
• Hb + CO2 = carbaminohemoglobin, Hb + O2 = oxyhemoglobin

  
• Why RBCs are excellent transporters of O2 and CO2

  • Biconcave form/shape (allows greater surface area to accommodate more gases)
  • Anucleated (absence of nucleus, more spaces for gases)
  • Round edges & resilient elastic structure (capable of bending at bifurcation of blood vessels, protect RBC from injury)
• Bright red color of blood indicates good oxygenated blood, dark bluish red color indicates poorly oxygenated or deoxygenated blood

  
• Clinical assessment of oxygenation

  • Well oxygenated tissues: pink color of gums, nostrils, cheeks, red color of lips
  • Poorly oxygenated tissues: bluish (cyanotic) color of gums, nostrils, lips due to prevalence of Hb without O2, white colored
• Hematology tests


  • Hematocrit or PCV
  • Morphology of RBC in different animals

  
• Hematocrit or PCV


  Test for the relative red blood cell mass, estimate the hemoglobin (Hb) concentration (PCV/3)

  
• Normal PCV range in various animals

  • Cat (30 - 45%)
  • Dog (37 - 55%)
  • Horse (32 - 48%)
  • Pig (36 - 43%)
  • Goat (22 - 38%)
  • Sheep (27 - 45%)
  • Cattle (24 - 46%)
• Factors influencing PCV values

  • Age
  • Breed
  • State of nutrition
  • Hydration status
  • Physical activity
  • Blood loss