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Blood vessels

Blood vessels

  • Three types of blood vessels are –

  1. Arteries
  2.  veins
  3. capillaries.

6.4.1 Arteries

  • Arteries are elastic vessels that are used to transport oxygenated blood away from the heart towards the body tissue. The only artery in the body which carries deoxygenated blood is the pulmonary artery.

6.4.2 Veins

  • Veins transport deoxygenated blood to the heart. Pulmonary vein is the only exception vein, conveys oxygenated blood from the lungs to the left atrium oxygenated blood from the lungs to the left atrium of the heart.
  • Veins contain numerous valves that prevent the backflow of blood.
  • Arteries and veins are usually joined together by capillaries in the tissue.
  • Walls of the veins and arteries consist of three layers:
  1. Tunica internal – the innermost layer is consisting of endothelium and an elastic membrane.
  2. Tunica media is the middle layer of smooth involuntary muscle and elastic fibres.
  3. Tunica external – an external layer was consisting of loose connective tissue.

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