Anatomy and patho

• Hemoglobin molecules can transport up to 4 O2, this means it is 100% saturated. Hemoglobin’s affinity for O2 increases as the saturation increases.
• Oxygen binding occurs in response to the high PO2 in the lungs
• Carbon monoxide (CO)

  • colorless, odorless, poisonous gas
  • CO has greater affinity than O2 for hemoglobin, Hb is the unable to deliver O2
  • disrupts cell respiration and may trigger hypoxia
• Hematology: study of blood and blood forming tissues = bone marrow, liver, spleen, lymph system
• Bone marrow is a soft substance in the core of bones. It is responsible for hematopoiesis = production of blood cells (RBC, WBC, platelet) generated by a self-regulated system
• The liver receives 24% of cardiac output. Its hematologic functions are the synthesis of plasma proteins (clotting factors and albumin) and the clearance of damaged or non functioning RBC in the circulation
• Spleen functions:

  • produce fetal RBCs
  • filter and reuse certain cells
  • lymphocytes and monocytes
  • 30% of platelets storage
• Blood function

  • Transportation: oxygen, nutrients, hormones, waste products
  • Regulation: fluid, electrolyte, acid base balance
  • Protection: coagulation, fight infections (WBC)
• Components of blood

  • 55% is plasma
  • blood cells: erythrocytes, leukocytes, thrombocytes
• Erythrocytes are composed of hemoglobin (iron compound and simple protein)
• Erythropoiesis is the production of RBCs

  • stimulated by hypoxia
  • controlled by erythropoietin
  • reticulocytes mature into erythrocytes in 48h
• Hemolysis is the destruction of RBCs

  • normal lifespan of RBCs is 120 days
  • release of bilirubin in the bloodstream
• 5 types of WBC

  • basophils
  • eosinophils
  • neutrophils (most common)
  • monocytes
  • lymphocytes
• Thrombocytes are involved in hemostasis, it is necessary for clotting to occur. The platelet plug is then stabilized by clotting factors of extrinsic and intrinsic pathways
• Pancytopenia is a decreased number of RBC, WBC and platelets
• Thrombocytopenia: decreased platelet count
• Anemia is the reduction in the number of RBC, quantity of hemoglobin or size of RBCs
• Anemia results in varying degrees of hypoxia because the main function of RBCs is oxygenation
• Causes of anemia are:

  • decreased RBC production
  • blood loss
  • increased RBC destruction
• Other types of anemia

  • megaloblastic anemia (large RBC)
  • cobalamin (vitamin B12) deficiency
  • folic acid deficiency
  • anemia of chronic disease
  • aplastic anemia
  • thalassemia
  • sickle cell anemia