Which tissue is in blood vessels

Blood vessels

About 150,000 kilometers of blood vessels supply the body with oxygen and nutrients. Blood vessels are used to transport nutrients and breathing gases as well as communication through chemical messengers.

In the veins, blood is transported from the body to the heart and in the thick-walled arteries it is transported away from the heart into the body. Arteries and veins are connected by a fine network of capillaries, in which the exchange of oxygen and nutrients takes place.

Structure of a blood vessel

Blood vessels can be thought of as elastic tubes. They are made up of different layers:

  • an inner layer (Tunica intima) of cells that delimit and seal the cavity. These so-called endothelial cells have a special function: They represent a barrier between the wall of the blood vessel and the blood. They prevent platelets from clumping together and forming a blood clot. Damage to this cell layer increases the risk of blood clots forming.
  • a middle layer (Tunica media), which primarily contains smooth muscles and elastic connective tissue.
  • an outer layer (Tunica externa or Adventitia), which contains collagen fibers and is used to anchor blood vessels in the area.

A distinction is made between blood vessels

  • Arteries: They distribute the blood that is pumped by the heart into the bloodstream, into the organs and tissues. Arteries have stronger muscles than veins because arteries have to carry blood from the pumping heart.
  • Veins: They collect the blood from the tissues and transport it back to the heart.
  • About this article

    Author: Editorial office
    Update: 09.03.2021
    Photo credits: Cover picture and illustration © Sebastian Kaulitzki / fotolia.com