Evidence of Work

Our Process

For this project, our goal was to successfully build a working heart valve model. We had to do this without any animal or human body being present, but we had to replicate the pumping function of the heart and the blood flow throughout it. The first step of this was to do research on the subject, looking into various aspects of the heart. This included sketching various perspectives of the heart, from the interior and exterior to the various valves. We also created multiple documents compliling the information we found and our conclusions from that. Some of these are below. One of the more important concepts was that of Young's modulus, which looks at the force of stress and strain for different materials in conjunction with elasticity.

Once we had all of our research completed, it was time to start testing. We tested the elasticity and Young's modulus of some of the materials we expected to be using, to see how they would compare in relation to the tissues inside the heart. We gathered this information and data and created a lab write up before moving on. My group and I then constructed our heart valve. We used a glove, a balloon, a funnel, water, and a tube (image below). We cut two holes in the fingers of the glove and stretched the balloon between them (also with a hole at the top). This allowed it to act as a pipe through the glove, and the balloon plus the glove acted as two layers, just like inside the heart. This space was also where the pumping function took place. When you squeezed this part of the glove, it pumped the "blood", also known as water, up and through the rest of our heart model. The water left the glove through a tube that ran into a funnel. The tube represents the blood leaving the heart, and the funnel is where the blood reenters the heart. The funnel ran into the glove again, and the process restarts. In between the funnel and the glove, there was laminated paper placed in a formation so that the water only flowed in one direction. The little paper leaflets would stay open if the water was flowing the correct direction, but would close up if the water began to flow the wrong way. We conducted a few tests with our model, gathered our data, and compiled everything into our final lab write up.

Our Work

Content

Important Concepts and Vocabulary

Aortic Valve - This valve has three leaflets. They open to let blood flow from your heart’s left ventricle to the aorta. The aorta is the largest blood vessel in your body. It brings oxygenated blood from your heart to the rest of your body. The aortic valve prevents backward flow from the aorta into the left ventricle.

Aorta - Pumps blood through the rest of the body.

Atria - Recieve blood.

Cardiac Muscle - Has multiple layers.

Chordae Tendineae - Attatch tricuspid and mitral valves to ventricles and are attatched to papilary muscles.

Conduction System - Controlled by the autonomic nervous system, it sends impulses to motivate the contractions of the heart.

Coronary Arteries - Circulate blood through the heart tissue.

Coronary Veins - carry deoxygenated blood from the heart tissue into the right atrium where it is then sent to the lungs.

Healthy Valve - A healthy valve is formed and flexible, opens all of the way so that blood can pass through, and closes tightly so that no blood leaks back into the chamber.

Interventricular Septum - Separates the right and left ventricles.

Mitral Valve - This valve has two leaflets. They allow blood to flow from the lungs into the left atrium. And they prevent backward flow from the left ventricle to the left atrium.

Myocardium - Part of the cardiac muscle. Contractions in the myocardium cause the heart's pumping, forcing blood in and out

Poracardium - Protective fibro serous sac that contains the heart and roots of the vessels.

Pulmonary Valve - This valve also has three leaflets. They allow blood to pump from the right ventricle to the pulmonary artery. This artery leads to the lungs, where blood picks up oxygen. The pulmonary valve prevents blood from going backward from the pulmonary artery to the right ventricle.

Sternal Costal - The surface of the heart.

Tricuspid Valve - This valve has three leaflets. They allow blood to flow from the right atrium to the right ventricle. They also prevent blood from flowing backward from the right ventricle to the right atrium.

Valves - Control blood flow through the four chambers.

Ventricles - Where blood can exit.

Heart Facts:

• The heart is one of the most difficult dissections to complete.

• It is close, but not perfectly symmetrical.

• There is fatty tissue around it and atricle flaps cover the atrium.

• The pulmonary trunk is located in front and at an angle.

Flowchart (Blood) for the Function of the Heart:

Lungs --> Pulmonary Veins --> Left Atrium --> Mitral Valve --> Left Ventricle --> Aortic Valve --> Aorta --> Body Tissue --> Vena Cava --> Right Atrium --> Tricuspid Valve --> Right Ventricle --> Pulmonary Valve --> Pulmonary Arteries --> Lungs

Steps of Blood Flow Through the Heart

• The right side of your heart takes in blood from your body and pumps it into your lungs.

• Your lung restore the blood with oxygen and send it back to the left side of your heart.

• Your aortic valve opens so that blood can flow from the left side of the heart to the aorta.

• The aorta pumps oxygen-rich blood to the rest of your body.

Aortic Valve Function: The aortic valve lets blood flow from the left ventricle to the aorta when open. It prevents blood from flowing in the wrong direction by closing, which keeps the blood from flowing back into the heart from the aorta. The aortic valve is made up of three sections of collagen, called cusps or leaflets. The leaflets open wide to allow blood to flow through and close tightly to prevent backflow.

Reflection

Overall, I think our heart valve project was a success, and I think my whole group was happy with what we accomplished. Two things that I think we did really well were our collaboration and critical thinking skills, but two things we could try and work on were our communication and conscientious learner skills. To start with what went well, our group collaborated really well on this project and we made sure we were doing things together for the majority of the time. We also used our critical thinking skills well to come up with a solution to the project that fit all of the requirements. It took awhile, but we eventually were able to finish and come out with a successful project.

On the other hand, for what we can continue to work on, communication was not that big of an issue, but throughout the course of the time frame, we may have run into a few small problems. This project included many different aspects, which had various assignments and other requirements to fulfill, and my group and I may not have communicated the best when it came to completing all of these in an efficient manner. We also could work on our conscientious learning skills because we ended up finishing the project towards the very end and feeling stressed about it. We were unable to find a solution that worked, and we struggled to do things in a timely manner. However, towards the end, when we finally found something that worked, we were able to bounce back to complete the project. Overall, I would think of our project as a success, as we met all of the requirements, turned everything in on time, and we constructed a working heart valve model.