There are three main types of blood vessels: arteries, veins, and capillaries. The total length of all blood vessels in an adult human is over 100,000 kilometers. Arteries carry oxygenated blood away from the heart to tissues and have thick, elastic walls to withstand high blood pressure. Veins carry deoxygenated blood back to the heart at low pressure and contain valves to prevent backflow.

1. BLOOD
VESSELS
BY: VAIBHAV

2. BLOOD VESSELS
There are three main types of blood vessels
•Arteries
•Veins
•Capillaries

3. ARTERIES
ARTERIOLES
CAPILLARIES
VENULES
VEINS

4. WHAT IS THE TOTAL LENGTH OF BLOOD
VESSELS?
Make a guess at the total
length, in kilometers, of all
the blood vessels in an adult
human.
100,100 Kilometers
That’s more than twice the
distance around the Earth at the
equator!

5. DO ALL BLOOD VESSELS CARRY THE SAME TYPE
OF BLOOD ?

6. BLOOD VESSELS
ARTERIES
• Carry blood away from the heart
• Thick muscular walls
• Lots of elastic tissue in wall
• Relatively small lumen
• Blood under high pressure
• Blood flow rapid
• Blood flows in pulses
• No valves

7. ARTERY

8. ARTERIES
• The elastic tissue in the artery wall allows the vessel to
‘give’ as blood surges through
• So, the artery wall first stretches as a result of the
high blood pressure
• before an elastic recoil of the wall pushes the blood
on its way.
• This swelling can be felt as a pulse where arteries
travel near the skin surface.

9. BLOOD VESSELS
Veins
• Carry blood back to the heart
• Thin muscular walls
• Little elastic tissue in the wall
• Relatively large lumen
• Blood under low pressure
• Blood flow is slow
• Valves prevent backflow of blood

10. VEIN

11. BLOOD FLOW IN VEINS- VALVES
• Veins have valves to prevent backflow.
• When blood flows along veins it pushes past the valves, which
can only open in one direction.
• If blood in a vein does flow backwards, it is trapped by closed

12. COMPARING CROSS-SECTIONS
• Compare the cross section of Vein and an Artery.
• Veins do not need to keep blood flowing quickly at
high pressure and so they have much thinner walls