Last week Kenny, Olivia and I completed our last anatomy and physiology lessons on the cardiovascular system. One of the last readings of the chapter was on “Vascular Vehicles” – the arteries, arterioles, veins, venules, and capillaries.
We read that children have about 200 million feet of blood vessels in their bodies while adults have over 500 million feet of blood vessels.
Pumping blood throughout those miles of vessels is the left ventricle’s job, and our pulse is the result of the rush of blood forced out of the heart with each and every beat. The text suggested a quick and easy project to observe the pulsation of blood in the wrist. Though we sort of botched our last experiment, this one seemed easy enough to pull together.
If you are interested in doing the project all you need are the following materials:
» clay or playdough (here is the homemade play dough recipe we use)
» science notebook or journal
HERE IS THE PROCESS:
1. Pinch off a small amount of clay or play dough and roll it into a ball.
Obviously not as much as Kenny jokingly has in his hand. Try 1/2″ to a 3/4″ pinch.
2. Insert the toothpick securely into the ball of clay/play dough.
3. Turn your wrist over and find your pulse on the side of your wrist nearest your thumb.
4. Once you find the pulse, place the clay/play dough ball directly over the area where you found the strongest pulse. Press down on the ball just enough for it to remain secure without you holding it.
5. Watch the toothpick as the blood rushes beneath it; the toothpick vibrates back and forth.
6. Using a stopwatch, count the number of vibrations the toothpick makes over a period of 60 seconds and record it in your science notebook or journal.
Repeat the steps multiple times and count the vibrations in 15 or 30 second intervals, multiplying by 4 or 2 (respectively) before recording.
Like I said, it is a simple project, but a great way to discuss how the heart beats to force blood through our bodies. This same blood carries oxygen and food to the various cells that need it. The movement made a nice visual of how very elastic the tissues in our arteries are, and how they easily expand without bursting when the pressure increases, returning to a smaller size when the pressure decreases.
We also counted and compared everyone’s rate around the table, as well as determined the average number of beats per minute of all the family.
Want more amazing heart facts?
» Have your child hold out their hand and make a fist. Their heart is about the same size as their fist. For adults, the heart is the size of about two fists.
» The heart beats about 100,000 times/day, 35 million times/year, and more than 2.5 billion times in an average lifetime.
» Our bodies have about 6 quarts of blood circulating through the body three times/minute. In other words, in a single day your blood will travel a total of about 12,000 miles!
Have any more interesting heart facts? Leave them in the comments below!
About the Author: A faith blogger and homeschooling parent, Heather Sanders is recognized for coining the term faithsizing to define her journey to find peace and contentment through Christ while embracing a simpler lifestyle.
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Hi. I’m Heather, a freelance writer living in Huntsville, a smallish town on the tail-end of the East Texas Pineywoods. Twenty years ago, I married Jeff, the love of my life, and shortly after, we chose to “go forth and multiply.” We have three kids: Emelie, Meredith and Kenny. We homeschool. It's what we do, and it works for us. Tired of feeling overwhelmed, we recently "faithsized" our family into a 960 square foot lake cabin in need of renovation. I write at HeatherSanders.com about faith and simplifying your desires so you can be content right here and right now
Original article and pictures take http://thepioneerwoman.com/homeschooling/2013/02/how-to-see-your-pulse/ site