Anatomical Heart Puzzle

Stuck at home? Trying to homeschool the kids or maybe learn something yourself? Now's as good of time as any to learn cardiac physiology! Or at least the basics. By assembling this modular puzzle, you'll learn the major chambers and blood pathway of the human heart.

-Paper. I included a file with the dimensions of each shape. It is approximately to scale, so you can print out the document to cut out if you wish.

-A ruler (if you're drawing out the shapes on your own paper instead of cutting them from the file). My measurements were in centimeters, but you can use it in inches for a larger model.

-Scissors

-Glue

Print and cut out, or sketch and cut out the shapes in the attached file. We will fold these into our parts. Remember not to cut on the lines drawn in blue, those lines will be folded along to make the 3D shape.

For easier learning, try different colors for each part, so you can identify them once the heart has been assembled.

Diagram: Wapcaplet / CC BY-SA (http://creativecommons.org/licenses/by-sa/3.0/)

Roll along the 4cm (or 4in) side of paper vena cavas as tightly as you can. Glue down the end to prevent the paper from unrolling.

We will being the journey through the heart with the superior and inferior vena cava. The purpose of the heart is to cycle oxygenated blood to your tissues, and then return that de-oxygenated blood back to your lungs, where it can be oxygenated again. Therefore, the blood entering your heart will be de-oxygenated. The blood from the upper body comes into the right side of the heart through the superior vena cava, and the blood from the lower body through the inferior. (In anatomy superior is toward the direction of your head while inferior is towards your feet).

Take one of the atriums and fold on the 1.2cm blue line so the symmetrical sides overlap. Use glue on the other flaps to stick the flaps onto the inside on the atrium, forming a 3D shape.

The first chamber the blood enters is the right atrium, which will contract, forcing the blood through the tricuspid valve.

Roll along the 4cm side of the tricuspid valve as tightly as you can. Glue down the end to prevent the paper from unrolling.

With the curved part of the atrium to the left, and the blue 1.2 folded line at the bottom, insert the superior vena cava from the top. (There should be a hole left there). Now cut a hole out of the bottom, where the blue 1.2 folded line would be, and insert both the inferior and tricuspid valve.

There should be three tubes stuck in the atrium. Use above photo for refrence.

After blood is pumped through the tricuspid valve, it closes shut to prevent backflow. The next chamber is the right ventricle.

Take the smaller of the two ventricles and glue the two top ends together. Fold the top flap down, leaving two holes at the top. Insert the tricuspid valve into one of the holes.

The right ventricle will contract and force the blood through the pulmonary valve into the pulmonary arteries, which will deliver the blood into the right and left lung for gas exchange (that's why there is a "T" at the top).

Roll the two pulmonary artery strips along the 4cm side, applying glue at the ends. As shown in the picture, cut a small "v" out of the middle of the shorter strip. Apply glue to one end of the longer strip and insert it into the "v".

In the lungs, carbon dioxide diffuses from the blood into the lungs, while oxygen from the lungs diffuses into the blood.

Apply glue to the other end of the long strip, and insert it into the last hole of the right ventricle.

Recently oxygenated blood returns from the lungs through the pulmonary veins. Notice that the unoxygenated blood left the heart through the pulmonary artery, and returns through the pulmonary veins. In fact, arteries carry blood away from the heat, and veins carry blood to it.

Roll two strips from the pulmonary veins along the 4cm side. Apply glue to the ends.

The blood enters the left atrium before passing through the mitral valve.

Take the last atrium piece and fold it in the same way as step 2. Now roll the mitral valve along the 4cm edge and apply glue at the end. With the 1.2cm line at the bottom and the curved part to the right, apply glue to the ends of the pulmonary veins, cut a hole in the top right of the atrium and insert the veins. Then apply glue to the end of the mitral valve, cut a hole into the bottom 1.2cm line, and insert the mitral valve in.

The last chamber is the left ventricle. It is here that blood gets pumped to the rest of the body, and for that reason, the left ventricle is more muscular and thicker than the other.

Take the last ventricle piece and fold it in the same manner as you did in step 3.

The first artery the blood goes through is the aorta. The aorta then branches off into smaller arteries to deliver oxygenated blood throughout your body.

Roll up the aorta pieces along the 4cm edge and add glue to the ends. Bend the longer strip in about a 130° degree angle, ⅓ of the way from the end. On this bent section cut two "v"s on the side opposite to the long section. Apply glue to the ends on the short strips and stick them into the "v"s. Stick the aorta into the remaining opening of the ventricle, so that the bent side is pointing towards the pulmonary veins.

You've now completed both sides of the heart!

To finish, intertwine the aorta with the pulmonary arteries.