ArteriesVeins

OB15 distinguish between arteries, veins and capillaries

Blood moves around us through tubes that cover our entire bodies. Some of these tubes go away from our heart and others return back to the heart. These 2 vessels are different.

We name them Arteries and Veins

It is easy to remember which one does what

Arteries go Away from the Heart

Veins go towards the Heart

talk through animation of the whole double pump system

http://www.sumanasinc.com/webcontent/animations/content/human_heart.html

The Heart acts like a Pump as so the Blood in the Arteries is under pressure, this pressure helps the blood get to all parts of the body quickly. But because of this pressure the tubes carrying the blood are also under large amounts of pressure and so the Arteries have quite thick walls.

Can you Label the two Blood Vessels?

Which one do you think is the Artery and which the Vein

Veins do not need such thick walls as the blood is being pushed into these vessels after going through the tissue.

However the blood in the veins have nothing pushing them back up to the heart, so in order to maintain the direction of the blood there are Valves in the Veins. These valves only allow blood to enter from one side, they then close until more blood wants to enter that section of the vein.