Hematology

• blood - the transporting fluid
• blood - transports oxygen and nutrients
• Blood composition

  55% Plasma, 45% formed elements
• 55% Plasma

  90% water, 10% proteins (albumin, immunoglobins, fibrinogens), Electrolytes, metabolic nutrients, metabolic waste products, hormones
• 45% formed elements

  98-99% erythrocytes, 1-2% WBCs and platelets
• blood has a pH of about 7.4
• an average adult of 70kg has a blood volume of 5 liters (5.3 quarts)
• Erythrocytes

  Male: 4.5-6.2 million/mm³

  Female: 4.2-5.4 million/mm³
• Leukocytes

  5000-10000 / mm³
• Thrombocytes (platelets) - 150000 - 450000 / mm³
• the appearance of red blood cell is referred to as biconcave (7-8 microns)
• an erythrocyte has a life span of 120 days
• red blood cell has the ability to transport oxygen and carbon dioxide, occurs as a result of a very important molecule called hemoglobin
• hemoglobin is made up of a protein called globin, and an iron compound called heme
• when the blood is oxygenated, it appears to be bright red
• deoxygenated blood appears to be dark-bluish red
• Hemoglobin reference values

  Male - 14 to 18 g/dL

  Female - 12 - 16 g/dL
• Leukocyte - primarily responsible for destroying foreign substances
• Diapedesis - WBC can pass through the thin walls of capillary to enter the tissues
• Phagocytosis - WBCs engulf or eat foreign substance or cellular debris
• Granulocytes - granules are present in the cytoplasm
• Agranulocytes - no granules are present
• First to respond to bacteria or a virus?

  Neutrophils
• Known for their role in allergy symptoms?

  Eosinophils
• Known for their role in asthma?

  Basophils
• Fights infections by producing antibodies?

  Lymphocytes
• life span of platelets?

  9-12 days
• Platelet plug - bleeding is diminished or halted as a result of platelets sticking to the site of injury
• Serotonin - causes the blood vessel to spasm or narrow and decrease blood loss until the clot is formed
• hemo means?


  blood
• stasis means?


  stopping
• hemostasis means?


  blood stopping
• Following an injury there are four major events

  involved in stopping the flow of blood at the injured

  site:

  1. Blood vessel spasm (vasoconstriction)

  2. Platelet plug formation

  3. Blood clotting (coagulation)

  4. Fibrinolysis or dissolving of the clot and return of

  the vessel to normal function
• Hematology - the study of the formed elements of the blood, including the red blood cells, white blood cells, and platelets