Making a 3-D model of a human heart is a fun science fair or craft project for an older student or a young student who has adult assistance. An easy medium to use is modelling clay, also known as plasticine. Simply mould the clay into the shape of a heart, label the various parts, and mount the finished project on a display board.
Unwrap the clay. Using a good illustration of the anatomy of the human heart for reference, mould one pound each of the red clay into the two bottom halves of the heart. One pound represents the anterior (front) side of the heart, and one pound represents the posterior (back) side.
Press your thumbs deeply into each piece of red clay, leaving a ridge in the middle. Each piece of clay will look like the bottom half of a walnut shell. Widen the pressed-out areas somewhat to represent the lower two chambers of the heart.
Mold two identical halves out of white clay to represent the top part of the heart. The pressed-out areas represent the upper two chambers of the heart.
Attach the two white clay pieces to the two red pieces, and seal them together by gentle finger pressure. Make sure the crack is completely gone so the top and bottom of each half stays together. The left and right side of the heart model that should fit together like a whole walnut shell but should not be sealed together (the model should show what the heart looks like from the outside and the inside).
Manipulate the red clay on one half to where the middle ridge is about a finger's-width wide. Mold the red clay up and over the white clay in the top half of the ridge. Make the ridge red throughout the entire piece. Make the ridge have a smooth, round look to it. This will represent the aorta in the heart model.
Roll out a "snake" of dark blue modelling clay about 1 to 2cm in diameter. This snake will represent the pulmonary artery and valve.
Attach the blue pulmonary artery next to the clay aorta that you made, above the ridge. Cross the blue artery over the aorta at the point where the white and red clay meet.
Use the illustration to determine how many parts of your model to label. For example, you may want to create labels for the right and left ventricles, right and left atria, superior and inferior vena cavae, pulmonary artery and vein, aortic arch, pulmonary and aortic semilunar valves, septum, myocardium, tricuspid and mitral valves, and coronary sinus.
Use a black fine-point marking pen to print the names of parts of the heart on a sheet of blank computer copy paper. If you have access to a computer and printer, you may wish to type the names in a list and print them out. Be sure to make each label easy to read but not so large that they dwarf the model, and allow space around each name for cutting.
Cut out the labels, and stick a straight pin or push pin in one end of each one.
Pin the labels to appropriate parts of the heart model. Refer to the illustration as you go to ensure that each part is labelled correctly.
If you need to add more clay parts to represent the veins and arteries coming in and out of the heart, do so.
Use hot glue gun to attach one half of the heart to an 8x10-inch mounting board, keeping the hollow side facing outward. Because of the weight of the model, you will need to use the glue liberally to achieve a secure mount.
Keep the other half of the heart model loose so it can be closed over the secured half. Lay it next to the secured half.
Add a title to the mat board with adhesive letters purchased at a craft, discount, or office supply store. If you prefer, you can create a title for your display on the computer, print out the sign, and secure it to the mounting board with hot glue.
If creating this model for a school science fair, be sure to read any guidelines provided by the teacher to determine if the labelling or mounting instructions need to be adapted to adhere to the fair's rules.