arteries

• Elastic arteries: thick-walled arteries with large resistance lumen

  • Aorta and its major branches: also called conducting arteries because they take blood from heart to medium sized vessels
• Elastics Arteries:

  • Elastin found in all three tunics, mostly tunica media
  • Contain substantial smooth muscle, but does nothing for vasoconstriction
  • Act as pressure reservoirs that expand and recoil as blood shoots out of the heart
  • Allows for continuous blood flow downstream even between heartbeats
• Elastic arteries give way to muscular Arteries or disturbing arteries:

  • take blood to body organs
  • account for most named arteries
  • have the thickest tunica media, sandwiched between elastic membranes, with more smooth muscle but less elastic tissue
  • Diameters range from pinky-finger size to pencil-lead size
  • Active in vasoconstriction
• arterioles or resistance arteries : smallest arteries

  • larger arterioles have all three tunics
  • smaller arterioles are only smooth muscle surrounding endothelial cells
  • lead to and controls flow into capillary beds with vasoconstriction and vasodilation
  • change diameters in turn changes resistance to blood flow
• If artery cut, blood spurts out because pressure is higher
• Blood is...

  the fastest in the aorta