Topic 9: Cardiovascular System 1

• What is the main function of the cardiovascular system?


  Deliver oxygen and remove carbon dioxide
• What is blood classified as?

  Liquid tissue
• What is the average blood volume in an adult male?

  5-6 litres
• What are the main components of blood?

  • Plasma
  • Red blood cells
  • White blood cells
  • Platelets
• What is the pH level of blood?

  Weakly alkaline, pH 7.4
• What are the functions of blood?

  Transport, metabolism control, homeostasis, protection
• What percentage of blood is plasma?

  55%
• What is the primary role of plasma proteins?

  Clotting factors and immune response
• What type of stem cell gives rise to blood cells?

  Hematopoietic stem cell
• What is the lifespan of blood platelets?

  10 days
• What is the main function of white blood cells?

  Protection against infectious diseases
• What are granulocytes and agranulocytes?

  Types of white blood cells based on granules
• What is the role of monocytes?

  Phagocytic macrophages in tissues
• What do B cells develop into?

  Plasma cells that produce antibodies
• What is the lifespan of red blood cells?

  120 days
• What is hemoglobin's primary function?

  Bind to oxygen and nitric oxide
• What is hemostasis?

  Sequence of responses to stop bleeding
• What are the three mechanisms that reduce blood loss?

  1. Vascular spasm
  2. Platelet plug formation
  3. Blood clotting (coagulation)
• What is thrombosis?

  Clotting in an unbroken blood vessel
• What determines blood type in the ABO system?

  Presence of A and B antigens
• What is the Rh factor?

  A red blood cell antigen
• What are the five main types of blood vessels?

  1. Arteries
  2. Arterioles
  3. Veins
  4. Venules
  5. Capillaries
• What is the primary function of arteries?

  Carry blood away from the heart
• What is vasoconstriction?

  Decrease in blood vessel diameter
• What is the structure of capillaries?

  Thin walls of a single layer of endothelium
• What is the role of fenestrations in capillaries?

  Allow substances to move in and out
• What is the importance of capillary exchange?

  • Rapid diffusion of oxygen and carbon dioxide
  • Short diffusion distance for nutrients
  • Large surface area for exchange
• What is the primary function of capillaries?

  Gas and nutrient exchange
• Why can only one blood cell fit in a capillary at a time?

  Capillaries have very narrow lumens
• What are the three layers of artery walls?

  • Endothelium
  • Smooth muscle (middle layer)
  • Outer layer
• What two major properties do arteries have due to their middle layer structure?

  Elasticity and contractility
• What are arterioles?

  Small arteries delivering blood to capillaries
• What is vasoconstriction?

  Decrease in blood vessel lumen diameter
• What is vasodilation?

  Increase in blood vessel lumen diameter
• What are the characteristics of capillaries?

  • Very small, thin walls
  • Single layer of endothelium
  • Highly branched and numerous
  • Narrow lumen for red blood cells
• What is the significance of fenestrations in capillaries?

  Allow substances to move in and out
• What are Starling Forces?

  Forces controlling fluid movement in capillaries
• What is blood hydrostatic pressure?

  Force exerted by blood on vessel walls
• What is blood colloid osmotic (oncotic) pressure?

  Pressure due to proteins in blood plasma
• Where does net filtration occur in capillaries?

  Near the arterial end