Human Anatomy at Colby

Lauren Shirley: Cardiology: Getting to the heart of the matter

February 22, 2015 · No Comments


One of the highlights of my experience in BI265j was the cardiac section and in particular, the heart dissections we got to do. I had a fairly solid understanding of the heart coming into the class from my EMT training. I knew that the blood came into the heart through the vena cava entered the right atrium passed through the tricuspid valve to the right ventricle, was pumped to the lungs through the pulmonary arteries to receive oxygen and then returned to the heart through the pulmonary veins into the left atrium then through the mitral valve to the left ventricle and out to the ret of the body through the aorta. What my EMT training had failed to teach me, however, was the beauty of this process, which is almost artful in its simplicity and elegance. This class gave me a greater appreciation of the elegance of the heart and the mechanisms behind its continuous beating. I was fascinated by the spread of electrical signal and its motion through the myocardium. The depolarization starting at the sinoatrial node, which spreads to the atrioventricular node then through the bundle of His and out to the Purkinje fibers is a highly linear path, simple yet powerful. While the lecture on the heart and studying plastic models in lab fascinated me, it was the opportunity to dissect the heart that truly solidified by understanding of it.


We dissected preserved cow hearts. Initially, I was impressed by the thickness of the muscle in the heart walls. It took quite a bit of work with a scalpel and scissors in order to get down into the different chambers of the heart. The sheer thickness of the walls and the work it took to get through them spoke to the sheer power of the heart as a muscle and the strength needed to supply a large body, such as a cow, with blood. Once inside the heart, I was fascinated by the sheer strength of the chordae tendinae, the fibers that keep backflow from occurring in the tricuspid and mitral valves. Despite pulling on these relatively thin cords, they didn’t tear! This further illustrated the necessary strength of the heart to me and the great pressure and quantity of blood that it pumps.


While it was really exciting to get to see a real life illustration of the models we had studies (that wasn’t color coded), it was even better to have a chance to share our newfound knowledge of the heart with the high school students who visited. I felt that teaching them what I knew solidified it in my mind. However, it was also exciting to see the “next generation” of young science students and how fascinated they were with the human body and its functions. I felt that my enthusiasm for cardiac function was almost contagious as I eagerly showed them how to dissect ad encouraged them to explore and understand the heart in front of them.





Long story short, this class got me pumped for cardiac anatomy and physiology and a possible career in cardiology. Ironically, I love the heart!

Categories: Bi265j · Lab · Special Activities
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