Circulatory system/ Blood vessels

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  • Created by: charlotte
  • Created on: 21-05-13 14:03

The mammalian circulatory system

  • The hepatic portal vein is the blood vessel that takes the products of the small intestine to the liver.
  • The coronary artery takes blood to the heart.
  • Renal- Kidneys
  • Hepatic-Liver
  • Coronary-Heart
  • Artery-Arteriole-Capillaries-Venule-Vein.
  • Ateries, arterioles and veins all have the same basic layered structure. From the outside inwards, these are:
  • tough outter layer, that resists pressure changes from both within and outside
  • muscle layer that can contract and control the blood flow
  • elastic layer that helps maintain blood pressure by stretching and recoiling
  • thin inner endothelium that is smooth to restrict friection and thin to allow diffusion
  • lumen is the central cavity of the vessel through which the blood flows.

Arteries

  •  Thick muscle layer  so the volume of blood can be controlled
  •  
    • Thick elastic layer to keep a high blood pressure so it reaches all over the body. 
    • Overall thickness of the wall resists the vessel bursting undeer pressure
  •  
    There are no valves because the blood is under constant high pressure and doesn't flow backwards


    Arterioles

-Arterioles carry blood, under lower pressure than arteries, from arteries to capilaries and cotrol blood flow between the two.

-Muscle layer is relatively thicker than in arteries as the contraction of this muscle layer

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