What are the three distinct types of blood vessels? Describe each in few sentences.
Arteries, veins, capillaries.
- 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.
- 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:
- 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