CIRC-BLOOD

• Circulatory System


  Blood: composition, clotting, disorders, blood types
• Systems


  • Circulatory system - heart, blood vessels, and blood
  • Cardiovascular system - only heart and blood vessels
  • Hematology - study of blood
• Circulatory System: Functions


  • Transport - Oxygen, CO2, Nutrients from digestive tract, Waste from metabolism, Hormones, Stem cells, other tissues
  • Protection - Inflammation, limit infection spread, Destroy cancer cells, Neutralize toxins, Initiate clotting
  • Regulation - Fluid distribution, blood pressure, stabilizes pH of ECF, Temperature
• Components of Blood


  • Erythrocytes (RBCs)
  • Leukocytes (WBCs)
  • Neutrophils
  • Eosinophils
  • Basophils
  • Lymphocytes
  • Monocytes
  • Platelets - fragments of certain bone marrow cells
  • Granulocytes
  • Agranulocytes
• Granulocytes


  Contain specific granules (protein containing secretory vesicles) and include three types of WBCs
• Agranulocytes


  Lack specific granules and include two types of WBC
• Components of Blood Plasma


  • Proteins
  • Nutrients
  • Electrolytes
  • Waste
  • Hormones
  • Gases
• Blood Plasma Proteins


  • Clotting, pathogen defense, transport of solutes
  • Produced by liver (except some globulins)
  • Albumin - Transport solutes, Buffer pH, Viscosity & osmolarity
  • Globulins - Solute transport, Clotting, Immunity
  • Fibrinogen - Precursor of fibrin, framework of blood clots
• Blood Plasma Components


  • Nitrogenous wastes - Urea (amino acid breakdown), Excreted through kidneys
  • Nutrients - Glucose, Amino acids, Fats, Cholesterol, Vitamins, Minerals
  • Dissolved gasses
  • Electrolytes (Na+ 90%)
• Blood Osmolarity


  Solute concentration in blood, High osmolarity - high water absorption - high BP, Sodium, proteins (colloid osmotic pressure)
• Blood Production


  1. Blood loss - Bleeding

  2. RBCs age and die

  3. Plasma components used or excreted

  4. Hemopoietic tissues - Spleen, Thymus, Bone marrow, Liver - until birth
• Erythrocytes (RBCs)


  • Pick up oxygen - tissues, Pick up carbon dioxide - unload into lungs
  • Lose nucleus and organelles
  • Anaerobic fermentation for energy, No aerobic resp. helps conserve oxygen for delivery
  • Cytoplasm - Hemoglobin (~33% of cytoplasm): provides red coloration, Carbonic anhydrase: CO2 + H2O - carbonic acid
  • Glycolipids on surface - blood typing
• Clinical significance of RBCs and Hemoglobin


  • Hematocrit - % of blood that is RBCs
  • Hemoglobin concentration - whole blood
  • RBC count - Values higher in men, Androgens stimulate RBC production, Periodic menstrual RBC loss, Inversely proportional to body fat %
  • 100 billion new RBC/day - bone marrow, Breakdown begins in spleen - liver
• RBC Homeostasis


  1. RBC count - Negative feedback, Low RBC count - hypoxemia (low blood oxygen levels), Kidneys detect hypoxemia - increase EPO output - increased RBC production, EPO = erythropoietin, Takes a few days to reach normal RBC levels

  2. Other causes of hypoxemia - Low atmospheric oxygen, Lethargy - active (exercise), Emphysema - can't be corrected
• Blood Doping Methods


  • Erythropoietin
  • Blood transfusion
  • Blood from higher altitudes
• RBC Disorders - Polycythemia


  • Overproduction of RBCs, Cancer of bone marrow, Other causes - Dehydration, Emphysema (e.g., from smoking), High altitude, Excessive exercise
  • Dangers - High BP & viscosity - congested vessels - heart strain, Embolism, stroke, heart failure
• RBC Disorders - Anemia


  • Lower than normal RBC count
  • Hemorrhagic anemia - Too much blood loss, excessive bleeding
  • Hemolytic anemia - RBC destruction
  • Inadequate erythropoiesis - Kidney failure - lack of EPO
  • Nutritional anemia - Iron deficiency, Low ability to carry oxygen
• RBC Disorders - Sickle Cell

  • Genetic, recessive allele, Heterozygotes - resistance to malaria
  • One amino acid change to hemoglobin - Normal glutamic acid - valine, Hydrophilic - hydrophobic AA
  • RBC "caves in" on itself - sickle shaped, Rigid, sticky, and pointed, Low binding to oxygen, Can agglutinate and clump together, Block small blood vessels
  • Heart failure, kidney failure, joint pain, Lysis of RBCs causes fatal positive feedback
• Leukocytes (WBCs)


  • Protection against infection & diseases
• Neutrophils


  • Most common (60%-70%), 3- to 5-lobed nucleus, Neutrophilia - rise in number during bacterial infections, Aggressively antibacterial - Destroys bacteria, Lysozyme and antimicrobial agents, Phagocytoses bacteria
• Eosinophils


  • 2% - 4% WBCs, Large rosy-orange granules; bilobed nucleus, Abundant in mucus membranes of Respiratory tracts, Digestive tracts, Urinary tracts, Granules (w/ chemicals that destroy large parasites) - Hookworms, tapeworms, etc., Elevated with allergies too
• Basophils


  • Rarest (<0.5% WBCs), Coarse, dark violet granules, S- or U-shaped nucleus, Granules - Histamine (Vasodilator, Speeds blood flow to damaged tissues), Heparin (Anticoagulant, Promotes WBC activity in affected area), Basophils are largely circulating cells; Mast cells are tissue residence - immediate hypersensitivity
• Lymphocytes


  • 25% - 33% WBCs, Bluish cytosol (scant to abundant); round; uniform dark violet nucleus, Destroys Cancer cells, Virus-infected cells, Foreign cells, Coordinate actions of other immune cells, Present antigens of foreign material, To activate other immune cells, Secrete antibodies, Immune memory
• Monocytes


  • 3% - 8% WBCs, Usually, largest WBC, Nucleus: ovoid, kidney-, or horseshoe-shaped, Can transform into macrophages, Phagocytosis, Destroys Pathogens, Dead neutrophils, Dead cell debris, Alveolar macrophage
• Next: Cardiovascular System - Heart