The Importance of Brushing Your Teeth - Part I

We've previously looked at the importance of brushing teeth to remove stains that certain foods may leave on the teeth.  This week and next we'll examine the importance of brushing teeth as a preventative measure.

The fluorine in toothpaste binds with calcium in your teeth to form calcium fluoride, which strengthens your teeth.

For this experiment, you'll want to make sure you use a fluoride toothpaste.  You'll see it listed in the active ingredients as sodium fluoride.

To represent our teeth, you'll be using an egg, as the shell is made of calcium, as are our teeth.

Coat one egg with toothpaste - all over.  Allow the egg to sit overnight with the toothpaste on it. 

The next day, wash the toothpaste off the egg.  Then place that egg in a cup/beaker of vinegar.  Place a second, untreated egg in a second cup/beaker of vinegar. 

The vinegar is an acid, as are many of the foods we consume, including, but not limited to fruit, tomatoes, and soda.

Observe the eggs over the course of the next 24 hours. 

You will notice that the cup with the untreated egg develops a foamy white substance on the top of the vinegar in a fairly short amount of time.  That foam is made of dissolved calcium - the shell is dissolving.  The treated egg does not produce nearly so much.

After 24 hours you'll notice that the untreated egg has completely lost its shell - you're left with a squishy egg.  The treated egg has a small amount of shell left.  It's on the squishy side - the fluoride doesn't completely protect it.  That's one of the reasons why you need to continue to brush your teeth - to constantly provide more fluoride and to help wash away the acid currently in the mouth.  It's also important to note that even with regular brushing, eating a diet high in acidic foods will, over time, wear on your teeth.  And lots of acidic foods without brushing your teeth is a recipe for ruining your teeth.

Body Systems: Nervous System: FREE Brain Mold

Looking for a fun prop for your Central Nervous System lecture?  Or a little Halloween fun? 

Jell-O/Kraft Foods is giving away free brain molds (you pay $2.95 for shipping). 

As previously mentioned, Education Innovations sells a brain mold with instructions for making a gelatin model the same size and mass as a human brain. 

I don't know how the free mold compares in size - I doubt it has the accuracy of the Educational Innovations model, but it's free!  It could certainly be useful for pointing out the parts of the brain in a basic anatomy lesson.  And, assuming you can find a bike helmet in which it fits appropriately, you could use it for a lesson in bike safety and the importance of helmets.  (Drop one gelatin brain without a helmet and another in a helmet and compare the damage).

I've ordered a free one and will do some experimenting with it once it arrives.  I'll keep you posted.  In the meantime, go here to get yours. 

Body Systems: Digestive System: Digestion in a Bag

Students model both mechanical and chemical digestion with simple materials.

Each student needs a zip-top bag, one or two crackers (saltines work well) and a small amount of soda.

The crackers are placed in the bag. 

Students smash the crackers to represent mechanical digestion - breaking apart the food. 

A small amount of soda is added to the bag.  After observing for a  few moments, students and squish the contents of the bag.  The soda contains acid, like your stomach does, which helps break down the food even further.  Once the food has been turned into a slurry, it is ready to be passed on to the intestines.

Measurement: The Symmetrical Human Body

Practice measuring length while learning a little more about your body.

The human body is proportioned with almost exact symmetry.  This symmetry allows a ballerina to leap gracefully, an athlete to run fluidly and a child to stop suddenly.  It also gives each of us the balance we need for our organs to function healthfully.

The human body's proportions are often expressed in terms of the length of your head.  Measure the following lengths and see how closely your body fits the mold. (These measurements are for adults, your students might not fit them yet as proportions change as we grow into adulthood).

Record all measurements in cm.

Measure the length of your head. ____ cm

The height of an adult is 8 times the length of the head, or 8 "heads".  Your height is ____ cm, which is ____ heads.

The distance from your hips to your feet is 4 heads.  This distance on you is ____ cm or ____heads.

The length of your head should equal the width of your waist.  Does it?

Your knees are 6 heads from the top of your head.  This length on you is ____ cm or ____ heads.

The width across the shoulders is 2 heads.  Your shoulder width is ____ cm or ____ heads.

The length of your foot equals 1 head.  Your foot length is ____ cm or ____ heads.

The length of your forearm from the inside crease of your elbow to the wrist bone equals 1 head.  This length on you is ____ cm or ____ heads.

Your waist is 3 heads down from the top of your head.  This length on you is ____ cm or ____ heads.

Your hands reach the middle of the thigh, or 5 heads down.  This distance on you is ____ cm or ____ heads.


**See what other proportions you can come up with.  For example:
--Your forearm is the same length as your foot.
--The length of your pinkie is the height of your ear.

Body Systems: Skeletal System: Simon Says

I learned of this idea from one of my workshop participants and I think it's a fun one.

After your students have learned the names of the bones, play a game of Simon Says.

Pair off your students and call out commands such as "Simon says touch your humerus to your partner's femur." 

It well help solidify your students knowledge of the bones, as well as provide some good laughs for everyone.

Science Wear

Photo from Science Wear

Science Wear makes these neat GUTS shirts.  They are a white shirt, with an outline of the organs screen printed on them.  Your students paint the shirts to make them their own, while reviewing some of the major organs.  The shirts are reasonably priced at $5 each, with free shipping if your order 25 or more.  There is a minimum order of 12.

If anyone who knows me (in real life) would like to get their hands on one or two shirts, let me know and we can put together an order to reach the minimum.  Or, even if you don't know me and just want one shirt, you can contact me and we'll see what we can do - obviously there would be some shipping involved, but less than ordering an extra 11 shirts that you don't really need or want anyway.  Leave a message in the comments (please leave your email address - they don't show up otherwise) or send me an email: adventures.in.science{at}gmail.com.

Science Wear also makes Atomic Attire (lab coats, aprons and t-shirts) and a Cell-ebrate Science t-shirt, but the GUTS shirt is my personal favorite.

Body Systems: Digestive System: Kinesthetic Model

 I love, love, love this activity from Bobbin Cave, part of the Access Excellence Fellows Collection.

Your students will actually act out the process of digestion - the props are so great and it's so much fun. 

First you'll need to make your food particle:

Place several M&Ms (or other brightly colored candy) in several small plastic bags (zip-top are preferable).

The bags of candy get placed in brown paper bags along with wadded up newspaper.

The paper bags, along with additional wadded up newspaper are placed in a large, thin plastic bag (you want something that rips open easily.

You'll need to gather some additional supplies:

--Large sponges

--Spray bottles filled with water - label half as "Saliva" and half as "Pancreatic Juices"

--Trash can

Use masking tape to make two parallel lines on the floor, 3 or 4 feet apart.

Have students line up, half on each line, facing each other. 

The path between them is the digestive tract.  They will all work together, using peristalsis, to push the food particle down the tract, as well as doing their individual jobs. 

Assign each student a job, based on his/her position along the tract. 

The first two students (the first student in each line) are molars.  Then saliva, pancreas, small intestine, blood, large intestine, and rectum. 

Double up on jobs as necessary to provide everyone with a role.  Explain what each student is responsible for doing in this activity:

• Molars: rip up food; the students will rip open the plastic bag when the get it
• Saliva: begins chemical digestion of food: the students will spray the bags and newspapers with their bottle
• Pancreas: continues chemical digestion of food; the students will spray the bags and newspapers with their bottles
• Small intestine: absorbs the nutrients and passes them to the blood; the students will search through the food particle to find the nutrients and hand the bags of nutrients to the blood
• Blood: distributes nutrients throughout the body; the students will pass out the nutrients to all the students (save this to do after all the digesting is complete)
• Large intestine: absorbs excess water; the students will use the sponges to soak up the water on the floor
• Rectum: removes waste: the students will place the remains of the food particle in the trash can

 I truly think this is a fantastic activity and is so useful in helping students learn the roles of the organs in the digestive system.  It takes a little bit of prep work (but not too bad) and if done properly, it cleans itself up! 

Body Systems: Cardiovascular System: Heart Diagram Roundup

All last week I shared some heart themed science activities.  In case you missed them, they were:
Beat Your Heart
Race Your Heart
Heart Squeeze
Heart Mambo
Heart Mold

And for today, I'll leave you with some printable heart diagrams.  Happy Valentine's Day!

You can find a plethora of heart diagrams on the Internet.  Here are several different ones - some with spots to label, some plain, and some in color.  To get the full-size image, click on the word link. 

From TeacherVision:
 

From Enchanted Learning (and the answers are here)

The Science Museum of Minnesota: (they also have some interesting animations here)

From edHelper (with labels here):

From Wikipedia:

Body Systems: Cardiovascular System: Heart Mold

It's probably too late to use this idea for this year, but it's always okay to start planning for next year. 

Educational Innovations (more on them coming up in the near future) makes this heart mold to be used in constructing a gelatin heart.  It includes instructions for making a hear the same size, shape, mass and color as an adult human heart. 

A little disturbing, a lot cool!


PS If you like this sort of thing, they also make a brain mold...

PPS Amazon sells a similar heart mold and brain mold.  They are less expensive, but I'm not sure how the size compares and I don't believe they include the instructions for getting the proper mass and color.

Body Systems: Cardiovascular System: Heart Mambo

You'll need to do a bit of prep work on this one, but it's a great learning tool, especially for your kinesthetic learners.

This activity originally comes from Janet Guadino and was shared at the 2007 Maitland Simmons Life Science Institute.


You'll need to make a series of signs for the floor. Use as many 'parts' as is appropriate for your students.  I've chose not to include the valves, but they are included in the list, parenthetically.

Blue Signs (written in blue or on blue paper)
Right Atrium
Right Ventricle(Tricuspid A.V. Valve)
(Pulmonary Semilunar Valve)
Pulmonary Trunk Artery
Veins
Veins
Vena Cava
Arrow (x12)

Red Signs (Written in red or on red paper)
Pulmonary Vein
Left Atrium
Left Ventricle
(Aortic Semilunar Valve) 
(Bicuspid/Mitral A.V. Valve)
Aorta
Arteries
Arteries
Arrow (x9)


Red and Blue Signs
Capillaries
Capillaries

Neutral Colored
Lungs

Arrange the cards on the floor as shown below (this is a condensed view, so they'll fit in one picture; you'll obviously want them spread apart so the path can be walked along):

In case you can't make it out from those shadowy pictures, the order of the signs is...

Lungs/Capillaries
Pulmonary Vein
Left Atrium
Left Ventricle
Aorta
Arteries
Capillaries
Veins
Vena Cava
Right Atrium
Right Ventricle
Pulmonary Artery
And back to the lungs


Have the students form a conga line behind you and lead them through the heart.  As you're traveling, chant "We're goin' through the heart, yeah!" Feel free to add some conga motions as well.  Pause at each location and call out where you're at/what you're doing. 

To close out the activity, have students place the following steps in order.  There is no right or wrong step to begin with, as it's a cycle, it's the order in which they appear that matters.  (I've written them in order for you, but you'd obviously mix them up before handing them to your students):

1 - Oxygen poor blood flows from the body into the right atrium

2 - The blood flows from the right atrium to the right ventricle

3 - The right ventricle pumps blood into the arteries that lead to the lungs

4 - In the lungs the blood picks up the oxygen and leaves carbon dioxide

5 - Oxygen rich blood leaves the lungs and enters the left atrium

6 - Blood flows from the left atrium into the left ventricle

7 - oxygen rich blood leaves the left ventricle and enters the aorta

8 - The aorta carries the oxygen rich blood to the rest of the body

Body Systems: Cardiovascular System: Heart Squeeze

Get an idea how much force it takes to squeeze blood out of the heart....

The force needed to squeeze a tennis ball is similar to the force needed to squeeze blood out of the heart.

Gather enough tennis balls so you have one ball for every two students (if you can get one for every student, they activity will proceed a bit faster, as you won't have to repeat every step).  Ideally, you'll find someone who plays tennis and can get you as many dead balls as you could want - your phys. ed. teacher might be able to help you find someone.

If you have the time, and feel inspired, you can draw a heart on the balls, but it's by no means necessary.

Ask students to squeeze the ball as many times as they think the heart muscle squeezes in 15 seconds (they need to give the ball a good, solid squeeze).  Their partner can time them, or you (the teacher) can call out the time for the whole class.  Each student should record their squeezes.

Allow the partner students to repeat this step.

Now the students will squeeze the ball each time the teacher counts.  Call out one beat per second.  Go for a full minute if your students can handle it. 

Repeat for the other students.

Gather students feedback about squeezing the ball at the pace.  Their hands will be rather tired.

Now tell them that pace was for a person at rest, but no one stays that still when they are awake.

Go for another full minute, this time calling out beats faster than one per second.  You're aiming for about 80 counts in one minute. 

Repeat for the other students. 

Body Systems: Cardiovascular System: Race Your Heart

 Can you move water as quickly as your heart can move blood? 

After this activity, you'll have a deeper appreciation for the work your heart does, every minute of every day for your entire life.

The heart pumps out 2 oz. (1/4 cup) of blood per contraction.  Cut some small paper/plastic cups down to hold 2 oz of water.  (Dixie cups hold 3 oz. - fill one with 1/4 cup of water, mark the water line and cut).

Place two containers/tubs next to each other, on top of towels or newspapers.  Fill one container 3/4 full of water.  

(This would be a good candidate for an outside activity, but in my part of the world, February is not the time to go outside and play in the water, so just be prepared with newspapers, towels and maybe a mop, just in case).

Practice using the cut-down cup to transfer water from one container to the second.  After you've practiced, return all the water to the original container.

When your partner/the teacher says to begin, use the cup to transfer water from one container to the second as quickly as you can.  Count the number of cup-fulls you transfer.  Your partner/the teacher will tell you to stop after one minute.

How many transfers did you make?  Did you come close to 80?  That's how many times your heart moved 2 oz. of blood during that minute. 

Try again and try to go even faster this time.  See if you can come close to matching your heart.

Body Systems: Cardiovascular System: Beat Your Heart

How much work does your heart really do?  The numbers are quite staggering... figure them out for yourself.


Part I: How many heartbeats in your lifetime?
Determine your pulse: count the number of beats in 15 seconds.

Multiply by 4 to get the number of beats her minute.  (Average is between 70 and 90).

Now, use that number to determine how many times your heart will beat, assuming an average lifespan of 78 years.


Part II: How Much Blood?
1/4 cup (2 oz.) of blood is pumped per contraction.  Using the number of beats per minute you calculated above, determine how much blood is pumped in one minute.  (Average is 20 cups = 5 quarts).

How many quarts of blood are pumped in a day?

How many gallons are pumped in a day?

Remember: 4 cups = 1 quart; 4 quarts = 1 gallon



Part III: How Much Does Your Blood Weigh?
About 10% of your weight is blood.

How many pounds of blood are in your body?

Body Systems: Digestive System: Digestive System Model

Use these props to help your students visualize the size of their digestive system.  This model is approximate for a 3rd grade student.

Esophagus: a straw

I was told that a straw is approximately the size of a 3rd grader's esophagus.  It seems like it might be a little narrow, but I can't find any exact figures to confirm or deny this.  My doctor brother-in-law says that the esophagus, when there's no food present, becomes pretty narrow, so this might be more accurate than I thought.

Stomach: small dish detergent bottle (sorry, the bottle accidentally got recycled... )

Here's a bonus to this prop: when it's empty and you squeeze it, it makes noise!  Just like your stomach!

Small Intestine: 24' of rope (about 1 cm diameter)

 Large Intestine: 6' of tubing (about 2 cm diameter)

Body Systems: Respiratory System: Model Lung

Creating a model lung is pretty simple.  You can find directions all over the internet, including right here!

Start with a plastic bottle, any size will do.  (Pictured here is a water bottle, but 2 liter bottles work as well).

Cut the bottom off the bottle.  If you're having students make their own lung, you may want to do this for them, and if the students are young, you may want to tape over the cut edge so no one gets cut.

Place a balloon in the neck of the bottle, and stretch the opening of the balloon over the opening of the bottle  (see the blue balloon in the above photo).

Cut the narrow part off of a second balloon.  Stretch the remaining balloon over the bottom of the bottle.

That's it.  

Now to use it.... 

The blue balloon represents a lung.  The red balloon is the diaphragm.  

When you breathe in, the diaphragm contracts (pull the diaphragm balloon down).  This lowers the air pressure in the chest cavity (because there's more room) and air fills the lungs.

When you exhale, the diaphragm relaxes (release the balloon, you can even push up on it a little).  The air pressure in the chest cavity increases and air flows out of the lungs.  

Basic Not Boring Workbooks

There comes a time when every teacher needs to use worksheets.  Some use them more readily than others, but everyone uses them some of the time.  

I like the worksheets found in the Basic Not Boring series.  They show a great variety of work (not the same sheet over and over again with different information plugged into it) and the fonts and sketches are more fun than basic text.  The work is intended for students in grades 6-8, and I have found it to be age and developmentally appropriate for my students.

Of course, it's unlikely that anything in these books is going to match your curriculum perfectly, since they aren't connected to a specific curriculum, but I've found them to be a good resource when I need something more.  

I have used:

Earth and Space Science

Life Science

 Physical Science

Human Body & Health

If you teach other subject areas, you can find books from the same series for math, history and language arts.