The human heart pumps blood throughout the body through arteries, capillaries and veins. The heart is separated into four chambers: the right chambers pump oxygenated blood from the lungs to the rest of the body, and the left chambers carry deoxygenated blood to the lungs. You can illustrate the heart's functions by using pop bottles to create a model of the human heart. Use the bottles to represent the chambers, coloured water to represent oxygenated or deoxygenated blood, vinyl tubing to represent veins and arteries, and bulldog clips to represent valves.
Remove the caps from the pop bottles. Pour out any remaining liquid, then clean and dry the bottles.
Using a hammer and nail, punch holes in all four bottle lids. Make the holes large enough for a piece of the short plastic tubing to fit through.
Connect two bottle caps together with a piece of four-inch vinyl tubing so that the cap tops face each other and there is one inch of tubing between them. Repeat this process with the other pair of caps.
Seal the holes in the caps with modelling clay.
Using your scissors, cut holes in the bottoms of two of the bottles. Make the holes large enough for the funnels to fit through. Cut similar holes two inches from the top of the other two bottles.
Thread a piece of 11/2-foot tubing through a hole in the side of one bottle. Push the tube inside the bottle so that it almost touches the bottom. Repeat this process with the other bottle that has a hole in its side, and seal these holes with modelling clay.
Attach the caps on all four bottles so that the tubing in the caps connects the bottles with holes in their bottoms to the bottles with holes in their sides.
Using electrical tape, tape the bottles with holes in the bottom together, and tape the bottles with holes in the sides to each other.
Add red food colouring to enough water to fill up one of each pair of bottles. Repeat this process with blue food colouring in the other bottle pair. The red water symbolises deoxygenated blood, while the blue water symbolises oxygenated blood.
Clip the bulldog clips on the tubing between the bottle caps. The clips symbolise valves, which let blood flow through veins in only one direction.
Tape the free ends of your long plastic tubing to the sides of the bottles with masking tape. This will prevent the water from squirting out and making a mess.
Stick your funnels into the holes in the bottoms of your bottles. Pour the red water into one bottle of a bottle pair, and the blue water into one bottle of the other pair.
Remove the bulldog clips to let water flow down through the tubes. Replace the clips when the water has travelled from one bottle to the other in each pair.
Squeeze the bottles that contain the longer tubing. The water will shoot through the tubes, representing blood travelling through arteries to carry oxygenated blood to the body or deoxygenated blood to the lungs.