What are the three distinct types of blood vessels? Describe each in few sentences.

1 Answer

Answer:

Arteries, veins, capillaries.

http://biology-igcse.weebly.com/arteries-veins-and-capillaries---structure-and-functions.html

Explanation:

Arteries

  • Carry blood away from the heart and deliver oxygen-rich blood to the tissues of the body (except for the pulmonary artery which carries deoxygenated blood to lungs)
  • Have very elastic wall which help to withstand the pressure created as the heart pumps the blood
  • Each artery is lined by smooth tissue and has three layers:

outer tunica externa, comparatively thicker middle layer tunica media and inner tunica interna/endothelium.

https://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0024676/

Veins

  • Carries deoxygenated blood towards the heart (except pulmonary veins which carries oxygenated blood from lungs)
  • Have thinner nonelastic wall
  • Unlike to arteries they are under low pressure and rely on muscle contractions to return blood to the heart
  • Have valves which prevent the blood from flowing in the opposite direction
  • Also have three layers:

Capillaries

  • Smallest of the body's blood vessels
  • Have very thin wall made of only endothelium
  • Perform oxygen, carbondioxide, nutrients and waste exchange between blood and tissues easily
  • They are connection between veins and arteries

http://www.passmyexams.co.uk/GCSE/biology/capillaries.html