blood vessels

• arteries have corrugated epithelial cells, elastic fibres and high blood pressure
• how is high blood pressure maintained in arteries?


  elastic fibres stretch and recoil

  stretching - volume increases, pressure decreases

  recoiling - volume decreases, pressure increases
• adaptation of vein: semilunar valve - situated between muscles so it's squeezed
• function of collagen fibres: to withstand the blood pressure
• all arteries have collagen fibres, elastic fibres and smooth muscles
• venules have no elastic fibres or smooth muscle