...and this is a sphygmomanometer cuff.

March 11, 2010 4:48 PM

How do I explain the concept of blood pressure to young kids?

I am volunteering at a local health fair this weekend, and one of my duties will be to show kids how to measure their blood pressure. I anticipate being asked what it is that I'm actually showing them to do, and just realized that I'd have a terribly difficult time explaining the idea of blood pressure to a child who might be too young to be aware that they have a cardiovascular system.

I don't expect them to end up with any grasp of the concept, but a funny and kid-appropriate definition would be quite helpful.

Most of the children there will be ages 3 to 8.

posted by halogen to Education (12 answers total)

You could use a large syringe to show that you need pressure to move blood (or jello!) up when it is held vertically.
posted by DarlingBri at 4:50 PM on March 11, 2010

What about using an analogy like sticking your finger over a garden hose to increase the pressure?
posted by Redmond Cooper at 4:54 PM on March 11, 2010 [1 favorite]

Response by poster: Although I actually have plenty of tubing and giant syringes at my disposal, I am not sure whether it'll be appropriate to bring my own props to the fair.
posted by halogen at 4:55 PM on March 11, 2010

Best answer: What? No! You gotta bring props! All the fun comes from the props, otherwise it's just fliers and posters and yawning.
posted by DarlingBri at 4:57 PM on March 11, 2010 [3 favorites]

You could inflate a length of rubber tubing with air or water. Have the kid squeeze it lightly while you firmly grip and relax your hold on another section. They should feel the tube expand a little against their hand when you grip down. Explain that the body has a bunch of tubes like the rubber tubing, only smaller and less elastic, called blood vessels, and that the heart contracts to push blood through the tubes. When it does, its the pressure increases, much like it did when you squeezed down on the tube.
posted by Good Brain at 5:07 PM on March 11, 2010 [1 favorite]

I think you could probably fill a balloon or latex glove or something with water, and squeeze it out fast or squeeze it out slow? Depending on how much mess is allowed, let the kids squeeze it, over a big tub of water or something? Same idea as the hose, more or less, but might be easier to manage away from running water. My suggestion is certainly an imperfect approximation, but I am thinking it might be enough to get the ideas of vasodilation, etc. across. Maybe?
posted by bunnycup at 5:07 PM on March 11, 2010

You could start the explanation with things they're familiar with such as bicycle tires, basketballs, or air mattresses. They're probably familiar with having a flat tire or an underinflated basketball that doesn't bounce, and from there you can make the point that things need to have the right amount of pressure to function properly.
posted by Rhomboid at 5:24 PM on March 11, 2010

Kids can be pretty literal. If you use props like balloons or tyres, take care not to give them the impression that high blood pressure will make them explode. (On second thoughts, fear of exploding is probably a great motivator for keeping one's heart health in check...)
posted by embrangled at 5:30 PM on March 11, 2010 [1 favorite]

Best answer: Explaining what pressure is may be useful, but in a lot of places in life more pressure is more good. Not so much the case with blood pressure.

Your blood is like the air inside a balloon. If you don't have enough air pressure inside your balloon, like if some of the air has been let out, it's not much fun. (Segue into why blood loss is a bad thing.)

If you have a balloon with the right amount of air pressure in it, you have a perfectly good balloon. You can squeeze it and such and in will stretch a bit, but not break.

But if you have too much pressure in there, and you squeeze the balloon, it won't last long. And your heart has to move blood around, which is like squeezing the balloon. And there is this other stuff that can collect over time inside your blood vessels, so it's like having too much air in a balloon and then your heart squeezes...so it's important to do things that get that other stuff out of your circulatory systems like exercise, etc.
posted by Kid Charlemagne at 5:41 PM on March 11, 2010

Describe a garden hose. When the hose is clear, water flows pretty easily. If you kink the hose, then it is harder for water to push through the hose - just like when there is arterial narrowing because of atherosclerotic plaques (or whatever terms are at their level). The more kinked up the hose is, the harder it is to push water through. The worse your arteries are, the harder the heart has to work to make blood flow through your arteries.
posted by honeybee413 at 7:05 PM on March 11, 2010

If you poke a hole in a person with high blood pressure, the blood spurts out really far.

If you poke a hole in a person with low blood pressure, the blood doesn't go very far.

Blood pressure is what makes your blood move around inside your body. The right amount of blood pressure, not too much nor too little, keeps you healthy.

(IANABiologyPerson, but I teach physics and have two sub-3-year-old daughters.)
posted by msittig at 10:09 PM on March 11, 2010 [1 favorite]

Put a straw in a juice box and squeeze it.
posted by buzzv at 3:58 AM on March 12, 2010