Your blood travels through your body very quickly. You probably already know that you can place your finger on certain points – like the radial artery in your wrist – and count the beats of your heart as it pumps blood throughout your body.
In this experiment, we will explore other ways to amplify your blood’s movement so that you can actually see a visual representation of it.
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Here’s what you need
- 1 lump of modeling clay or plastic putty
- 1 stopwatch
- 1 coffee stirrer straw
- 1 partner
Here’s what you do
- Your radial artery in the wrist carries your blood from your heart down to your hand. Use your index and middle fingers to find your pulse in the radial artery on the inside of your left wrist.
- Put a small, flat circle of clay on the spot where you found your radial artery’s pulse.
- Push one end of the straw carefully into the clay or putty so that it’s standing up, perpendicular to your arm.
- Using the stopwatch, record how many beats you see per minute by observing how many times the straw bounces.
What’s going on?
Your blood is pushed out of a chamber by the muscles of your heart and into your arteries, creating a force which is measurable. This is called your blood pressure. Systolic pressure is the resistance to outward blood flow through the arteries. The diastolic pressure is a measure of the blood flowing back to the heart to be oxygenated. Average blood pressure would be recorded as 120/80. Healthy blood pressure is important, since high blood pressure is a risk factor for many illnesses such as heart disease and stroke.
A few more random blood facts for you: there are 4 main types and they are A, B, AB and O. Oxygen binds to hemoglobin in your red blood cells, making an iron-rich compound. This makes the bright red color.
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No – any should work fine.
Do you have to have a straw that small?