Blocked and normal arteries

What's this Science Bite about?

To be healthy each cell in our body requires a constant supply of oxygen. Oxygen enters our body each time we breathe in and is transported through our bodies by our blood.

The movement of blood through our bodies is called circulation and is controlled by the circulatory system which is made up of the heart, blood and blood vessels.

Your heart is a powerful muscle that acts like a pump to send blood to the lungs and the cells in your body. The blood travels through a network of blood vessels called arteries and veins.

Arteries carry oxygen rich (oxygenated) blood away from the heart to the cells in your body. The cells use the oxygen and produce carbon dioxide and other waste. Veins carry the oxygen poor (deoxygenated) blood back towards the heart.

The heart sends the blood back to the lungs to be oxygenated and the cycle begins again.

What happens when something goes wrong with the circulatory system?

Try our experiment to find out.

What you'll need

What you need for the blocked and normal arteries demo

  • Download and print the Blocked and normal arteries guide:
    icon Blocked and normal arteries (546.98 kB)
  • 2 beakers of water with red food colouring added
  • 2 plastic cups
  • 2 straws of different thicknesses
  • Dish for catching water
  • Blu tac
  • Scissors
  • Tape
  • Pin

How to do the experiment

  1. Put a strip of tape around each cup close to the bottom.

  2. Use a pin to make a hole in the side of each cup, near the bottom. Carefully widen the holes so they fit each straw comfortably. The wider straw will require a bigger hole.

  3. Trim each straw to approximately 5 centimetres.

  4. Place the straws through the pre made holes.

  5. Use blu tac to seal the inside of the hole around the straw so that water cannot leak out of the hole.


    Use blu tac to seal the inside of the hole around the straw so that water cannot leak out of the hole.
  6. Place the cups side by side in the dish. Make sure the straws are pointing down so that the water can flow out. Pour in the coloured water.

  7. The coloured water will flow out both straws but at different rates.


    The coloured water will flow out both straws but at  different rates

Find out more...

What's happening?

The cup with the thin straw empties more slowly.

This replicates what happens in the body when an artery becomes blocked.

Heart disease occurs when the blood supply to your heart is blocked by a buildup of fatty substances, known as plaque, in the walls of the arteries. As the plaques grow larger, the arteries narrow.

Narrowing of the arteries leads to a decrease in the volume of oxygenated blood that can reach the heart which can lead to chest pains and heart attacks.

The plaques may become dislodged and form clots in the blood that block the flow. This can also cause heart attacks and strokes.

Visit BodyWorks at Glasgow Science Centre - an interactive exhibition all about human health and wellbeing in the 21st Century.

Curriculum links

Body systems and cells

SCN1-12a/2-12a/3-12a

Physical well being

HWB 1-15a/ 2-15a/ 3-15a

TripAdvisor

Glasgow Science Centre