Friday, 22 February 2013

2.65 describe the structure of arteries, veins and capillaries and understand their roles

Arteries
Take blood away from the heart
Blood in them is under high pressure
They are delivering blood to an organ
Thick, muscle wall; small lumen (to give high blood pressure)

Veins
Take blood to the heart
Blood is under low pressure
Their blood is returning from an organ
Relatively thin wall; large lumen (to give ow blood pressure)
Valves stop blood flowing back in the wrong direction

Capillaries
Exchange is taken place
Very thin cell walls (one cell thick) so that substances can diffuse easily
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7 comments:

  1. ahopster29 December 2014 at 07:16

    Also the blood in arteries is oxidised and the blood in veins are de-oxidised

    ReplyDelete
  2. Unknown18 January 2016 at 12:25

    Expect for the pulmonary artery and pulmonary vein where it is the other way around

    ReplyDelete
    Replies
    1. JumpStart www.jump-start.uk.com15 April 2017 at 05:27

      That's incorrect the pulmonary artery takes blood to the lungs (away from the heart) and the pulmonary vein takes blood to the heart (from the body)

      Delete
    2. Unknown18 April 2017 at 14:31

      yep

      Delete
    3. Anonymous12 May 2018 at 05:26

      he meant on the oxidation thing

      Delete
  3. Mike Tsang26 June 2017 at 03:03

    The Biology Syllabus has changed.... New Syllabus Blog:

    http://igcse-biology-2017.blogspot.hk

    ReplyDelete
  4. SophieRice26 June 2017 at 18:19

    more at

    http://igcse-biology-notes.blogspot.hk/2017/06/265-describe-structure-of-arteries.html

    ReplyDelete

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