cardiovascular

• Functions of the circulatory system

  • Transport of gases
  • Distribution of nutrients and hormones
  • Transport of toxins and cell waste
• Main components of the circulatory system

  • Heart
  • Blood
  • Blood vessels (veins, arteries, capillaries)
• Arteries


  • Carry blood away from the heart
  • Don't have valves (pressure is high)
  • Have walls with thick layer of smooth muscle
• Veins


  • Carry blood toward the heart
  • Have valves to prevent backflow (pressure is low)
  • Have walls with thin layer of smooth muscle
• Capillaries


  • Smallest blood vessel, one cell thick (squamous epithelium)
  • Allow exchange of materials between blood and other tissues
  • Connect veins with arteries
  • Pressure is very low (could explode if high)
• Pulmonary Circuit


  1. Directs blood from the heart through the lungs, where carbon dioxide is exchanged for oxygen, and back to the heart (flow from the heart to the lungs and back)

  2. Pulmonary arteries carry blood with CO2 from the right side into the lungs

  3. Gas exchange happens in the lungs

  4. Pulmonary veins return blood with O2 to the heart
• Systemic Circuit


  1. Carries blood between the heart and the rest of the body, where oxygen is exchanged for carbon dioxide (flow of blood from the heart to the body and back)

  2. The heart pumps blood with O2 into the body's largest artery: the aorta

  3. Gas exchange happens in the body tissue

  4. Blood with CO2 from tissues returns to the heart through the superior and inferior vena cava
• The Cardiac Cycle (the heartbeat)


  1. The two atria contract simultaneously (atrial systole)

  2. The two ventricles contract simultaneously (ventricular systole)

  3. All chambers then relax (diastole)
• Blood Components


  • Plasma (55%, 90% water, pale yellow fluid where things float in)
  • White blood cells and platelets (1%, immune cells)
  • Red blood cells (44%, for O2 transport)
• Atherosclerosis


  Buildup of plaque (fatty material including cholesterol, connective tissue, white blood cells, smooth muscle cells) within walls of arteries obstructs blood flow and decreases compliance of vessels
• HDL


  "Good" cholesterol
• LDL


  "Bad" cholesterol, more deposit of this one causes lipids to be oxidized due to O2 in the blood, this causes lipids to calcify and form plaque
• Atherosclerosis treatment


  1. Plaque flattened by balloon angioplasty

  2. Metal mesh placed to keep arteries open
• Coronary Artery Disease (CAD)


  Type of atherosclerosis that occurs in the arteries that supply the heart with blood (coronary arteries), can become a family disease (passed down)
• Coronary Artery Disease treatment


  1. Medication

  2. Changes to diet and exercise

  3. Angioplasty

  4. Stent

  5. Coronary bypass procedure (veins from another part of the body are placed to divert blood around two blocked coronary arteries)