BLOOD

• Functions of blood

  • Transport
  • Nutrients
  • Hormones
  • Wastes
  • Body heat
• Blood pH


  Slightly alkaline, between 7.35 and 7.45
• Blood temperature

  Slightly higher than body temperature, at 38ºC or 100.4ºF
• Amount of blood in a healthy adult

  About 5–6 liters
• Blood as a percentage of body weight


  8 percent
• Male


  Has higher oxygen demands than the female because of Androgen
• Components of blood

  • Plasma
  • Formed Elements
• Plasma


  Liquid part of blood, 50-60% of total blood volume, includes many dissolved substances
• Substances dissolved in plasma

  • Nutrients
  • Salts (electrolytes)
  • Respiratory gases
  • Hormones
  • Waste products
• Plasma proteins

  • Albumin
  • Clotting proteins
  • Antibodies
• Erythrocytes (RBCs)

  Biconcave, 2μm thick, 7.5-8μm wide, normal count is 5 million per cubic millimeter, carry hemoglobin, anucleated, deformable
• Erythrocytes (RBCs)


  • Deformable due to prostaglandin enable RBC to pass through blood vessels
• Homeostatic imbalance of RBCs

  Anemia - decrease in oxygen-carrying ability of blood due to lower-than-normal number of RBCs or abnormal/deficient hemoglobin
• Homeostatic imbalance of RBCs

  Sickle Cell Anemia - results from abnormally shaped hemoglobin
• Homeostatic imbalance of RBCs

  Polycythemia - excessive or abnormal increase of RBCs, slows blood flow and increases blood viscosity
• Leukocytes (WBCs)


  • Crucial in body's defense against disease, complete cells with nucleus and organelles, able to move into and out of blood vessels, move by amoeboid motion, normal range 4,800 to 10,800 per mm3 of blood
• Types of leukocytes

  • Granular (10-14 days, red bone marrow)
  • Agranular (2-3 days, lymphatic tissues)
• Neutrophils


  Phagocytic, first line of defense for bacterial infection, most numerous WBC, multilobed nucleus, pink cytoplasm with fine granules, function as phagocytes, numbers increase during infection, normal range 3,000–7,000 per mm3 of blood (40–70% of WBCs)
• Eosinophils


  Phagocytic, present in allergy and parasitic infections, blue-red nucleus, brick-red cytoplasmic granules, function to kill parasitic worms and play a role in allergy attacks, normal range 100–400 per mm3 of blood (1–4 percent of WBCs)
• Basophils


  Phagocytic, contain heparin to prevent intravascular clotting, release histamine, rarest of the WBCs, large histamine containing granules that stain dark blue, normal range 20–50 per mm3 of blood (0–1 percent of WBCs)
• Lymphocytes


  Non-phagocytic, present in viral infections, types are B & T lymphocytes which contain antibodies, source of other cells like monocytes and fibroblasts, large dark purple nucleus, slightly larger than RBCs, reside in lymphatic tissues, play a role in immune response, normal range 1,500–3,000 per mm3 of blood (20–45% of WBCs)
• Monocytes


  Phagocytic, important in chronic infection, known as Macrophages if found in tissues, largest of the white blood cells, distinctive U- or kidney-shaped nucleus, function as macrophages when they migrate into tissues, important in fighting chronic infection, normal range 100–700 per mm3 of blood (4–8 percent of WBCs)
• Fever


  Your body is trying to kill the virus or bacteria that caused the infection, fever activates the immune system
• Leukocytosis


  WBC count above 11,000 cells per mm3 of blood, generally indicates an infection
• Leukopenia


  Low WBC count, commonly caused by certain drugs such as corticosteroids and anti-cancer agents
• Leukemia


  Marrow becomes cancerous, numerous immature WBCs are produced
• Platelets (Thrombocytes)

  Fragments of megakaryocytes, needed for the clotting process, normal count is 300,000 per mm3 of blood, life span of 4-5 days
• Hemostasis

  1. Vasoconstriction

  2. Platelet plug

  3. Blood coagulation
• ABO blood group

  Based on presence or absence of antigens A and B, types are A, B, AB, and O
• Rh blood group


  Named for the eight Rh antigens (agglutinogen D), most individuals are Rh+ (Rh-positive)
• Blood antigens


  Genetically determined proteins that the body recognizes as foreign and the immune system may attack, most are foreign proteins, we tolerate our own "self" antigens
• Antibodies


  The "recognizers" that bind to foreign antigens, used to "type" blood