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Lecture Notes

Here you see a picture of the heart, and you should be familiar with its basic anatomy for this course. It's an amazing organ that pumps blood through our bodies 24 hours a day, 7 days a week, without us ever having to think about it. Maintaining the health of your heart and the entire circulatory system is integral to leading a healthy lifestyle. Some basic anatomical structures of the heart that you should be familiar with, it has four chambers: both the right and left atria, which are at the top of the heart; the right and left ventricles, which are at the bottom of the heart—and these are, the right and left are oriented based on the heart being inside someone's chest, so it's opposite of what you see when you're looking at the screen here. There are also four valves, all of which are one-way to ensure that blood only moves through our heart in one direction. There's an electrical conduction system that allows the heart to beat without conscious thought. So unlike our skeletal muscles in our body that we'll talk about later in this course, this system is regulated by the sinoatrial node, or the SA node, and it's all autoregulated; we don't have to consciously think about making our heart beat. That SA node is also known as the pacemaker of the heart, and it's what keeps that regular rhythm of our heart. It's located in the right atrium, and there are many other important parts to this electrical system, but you're really only responsible in this course for that SA node. And I would encourage you to read the section titled "The Heart" in your textbook to familiarize yourself with the anatomy of the heart. This was a very brief introduction to those main components, but you should be able to label an entire picture of the heart here for this course.