1. Blood vessels

• Blood vessels are classified according to their size, structure, function, and location.
• Type of Blood vessels:

  -Arteries

  -Arterioles

  -Capillaries

  -Venues

  -Veins
• Arteries


  • All tubular organs including blood vessels have a hollow center called the lumen
  • Most blood vessels have 3 layers to their walls
• 3. Tunica intima or interna


  The innermost layer and consists of the endothelial cell and its basement membrane
• 2. Tunica Media


  The middle layer and is the thickest, consists primarily of elastic fibers and/or smooth muscle
• 1. Tunica adventitia or externa


  The outermost layer made primarily of elastin and collagen
• Arteries all have 2 primary properties

  1. elasticity
  2. contractility - if smooth muscle wall of an artery contacts, it leads to vasoconstriction