Monday, 7 January 2013

AS Biology: Mammalian transport system

Artery


  • Thick walls with muscles present
  • a lot of elastic tissues
  • Small lumen
  • no valves except in the pulmonary artery and aorta
  • ablt to constrict
  • not permeable
  • carries blood FROM heart 
  • carries oxygenated blood
  • withstands high pressure
  • blood moves in pulses
Vein

  • Thinner wall muscles present
  • some elastic tissues
  • larger lumen
  • has semi lunar vales throughout
  • cannot constrict
  • not permeable
  • carries blood TO heart
  • carries deoxygenated blood
  • low pressure
  • no pulses
Capillary
  • Thinnest wall with no muscles present
  • no elastic tissue
  • larger lumen
  • no vales
  • cannot constrict
  • permeable
  • carries blood to ad from the heart
  • carries both oxygenated and deoxygenated blood
  • pressure in between veins and arteries
  • no pulses

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