tunica adventitia

  • circulatory system

    • arteries

      TITLE: artery
      ...pierced with many openings. The tunica media, or middle coat, is made up principally of smooth (involuntary) muscle cells and elastic fibres arranged in roughly spiral layers. The outermost coat, or tunica adventitia, is a tough layer consisting mainly of collagen fibres that act as a supportive element. The large arteries differ structurally from the medium-sized arteries in that they have a...
    • description

      TITLE: human cardiovascular system: The blood vessels
      SECTION: The blood vessels
      ...In larger vessels the tunica media is composed primarily of elastic fibres. As arteries become smaller, the number of elastic fibres decreases while the number of smooth muscle fibres increases. The tunica adventitia, the outermost layer, is the strongest of the three layers. It is composed of collagenous and elastic fibres. (Collagen is a connective-tissue protein.) The tunica adventitia...
    • veins

      TITLE: vein (blood vessel)
  • human digestive system

    TITLE: human digestive system: Esophagus
    SECTION: Esophagus