structures of the cardiovascular system

• superior vena cava
• right AV valve/ tricuspid valves
• tri before you bi
• right ventricle
• pulmonary veins carry oxygenated blood
• pulmonary arteries carry deoxygenated blood
• left AV valves/ bicuspid valves
• chordinae tendinae prevent the valves from inverting- prevents the backflow of blood
• left side has thicker cardiac muscle
• aorta is at the top and base of the heart
• types of blood vessels:

  • arteries
  • arterioles
  • veins
  • capillaries
• blood vessels have 4 layers of tissue:

  • tough outer layer (collagen)
  • smooth muscle layer
  • elastic layer
  • inner lining (endothelium)
• the hole in blood vessels is called the lumen
• Artery wall:

  • thick walls for high pressure
  • thick layer of elastic tissue and smooth muscle encased in collagen
  • STRETCH AND RECOIL
• Arteriole:

  • branch off from arteries
  • carry blood from arteries to capillaries
• Arteriole wall:

  • thinner elastic layer: decreased pressure
  • thicker muscle layer
  • CONSTRICT AND DILATE: allows body to decide where blood goes- vasoconstriction and vasodilation
• Capillaries:

  • narrow and thin: huge SA:V ratio
  • small holes between endothelial cells
  • low pressure
• Capillary walls:

  • no muscle, collagen or elastic layer
  • one cell thick for substance exchange
• Veins:

  • carry blood back to the heart
  • low pressure
  • usually blood is deoxygenated
• Vein walls:

  • not thick
  • wide lumen to maximise blood flow
• semi lunar valves are in the veins to prevent backflow of blood
• Skeletal muscles contract veins to help blood get from the legs to the heart
• only capillaries carry out exchange