Haematology

• What are the main components of blood?

  RBC, WBC, platelets, plasma
• What is the composition percentage of plasma in blood?

  55%
• What percentage of blood is made up of WBCs and platelets?

  1%
• What percentage of blood is composed of RBCs?

  45%
• What are the important plasma proteins?

  Albumin, globulin, fibrinogen
• What is the range of albumin percentage in plasma proteins?

  37-60%
• What are the types of WBCs (leucocytes)?

  Neutrophils, lymphocytes, monocytes, eosinophils, basophils
• What is haematopoiesis?

  Production of blood cells in bone marrow
• What is the shape of RBCs and why is it important?

  Biconcave for large surface area for diffusion
• How many molecules of O2 can one molecule of haemoglobin pick up?

  4 molecules
• What gives RBCs their red appearance?

  The iron in the haem
• What is the lifecycle of RBCs?

  Iron & nutrients absorbed, produced in bone marrow
• How long do RBCs last before being destroyed?

  Approximately 120 days
• Where are RBCs broken down?

  In the liver by macrophages
• What happens to haemoglobin after RBC destruction?

  Conserved & split into heme and globin
• What is heme further broken down into?

  Iron and biliverdin
• What happens to iron after RBC breakdown?

  Recycled back into bone marrow
• What happens to biliverdin after RBC breakdown?

  Converted into bilirubin and excreted
• What is the function of WBCs?

  Fight infection and protect the body
• What does blood plasma transport?

  Gases, nutrients, electrolytes, proteins
• What are the three stages of haemostasis?

  1. Vessel spasm (vasoconstriction)
  2. Platelet plug formation
  3. Blood coagulation
• What occurs during vessel spasm in haemostasis?

  The vessel constricts to minimize blood loss
• What do platelets do during an injury?

  Congregate at the site and form a plug
• What activates prothrombin in blood coagulation?


  Prothrombin is activated to form thrombin
• What does thrombin activate?

  Fibrinogen to form fibrin
• What is the role of fibrin in blood coagulation?

  Forms the clot and stops bleeding
• What are the blood groups and their characteristics?

  • Blood group A: A antigen, anti-B antibody
  • Blood group B: B antigen, anti-A antibody
  • Blood group O: No antigens, anti-A & anti-B antibodies (universal donor)
  • Blood group AB: A & B antigens, no antibodies (universal recipient)
• What happens if blood type A receives blood type B?

  Anti-B antibodies will attack B cells
• Where are antibodies found in relation to blood groups?

  In the blood plasma
• What is the Rhesus factor?

  Positive or negative antigens on cells
• What happens to Rhesus negative cells when exposed to Rhesus positive blood?

  They produce antibodies against Rhesus positive
• What is the risk for a Rhesus negative mother with a Rhesus positive fetus?

  She may produce antibodies against fetal RBCs
• What is given to Rhesus negative mothers during pregnancy?

  Prophylactic Anti-D
• What is the purpose of the Kleinhauer test?

  To determine fetal blood in maternal circulation
• What does the Kleinhauer test measure?

  How much fetal blood has passed into maternal circulation
• What is the significance of fetal hemoglobin in the Kleinhauer test?

  • Fetal hemoglobin is different from maternal hemoglobin
  • Helps determine the amount of fetal blood in maternal circulation