This lesson contains background about the blood vascular system and the heart. Also, the different sizes of capillaries, veins, and arteries, and how they affect blood flow through the system. We will then proceed to talk about the heart's function in the blood vascular system. This will lead into a discussion of heart valves, how they work and what might cause them to fail. Then we will discuss prosthetic heart valves.

In this lesson the students will learn how the heart functions. Students will be introduced to the concept of action potential generation. The lesson will explain how action potential generation causes the electrical current that causes muscle contraction in the heart. Students will be introduced to the basic electrical signal generated by the heart; P, QRS, and T waves. The lesson will approach the heart from an engineering standpoint and encourage students to design ways to improve heart function. Students will also learn the basic steps of the engineering design process.

Students are presented with the unit's grand challenge problem: You are the lead engineer for a biomaterials company that has a cardiovascular systems client who wants you to develop a model that can be used to test the properties of heart valves without using real specimens. How might you go about accomplishing this task? What information do you need to create an accurate model? How could your materials be tested? Students brainstorm as a class, then learn some basic information relevant to the problem (by reading the transcript of an interview with a biomedical engineer), and then learn more specific information on how heart tissues work their structure and composition (lecture information presented by the teacher). This prepares them for the associated activity, during which students cement their understanding of the heart and its function by dissecting sheep hearts to explore heart anatomy.

Students learn how to take blood pressure by observing a teacher demonstration and then practicing on fellow classmates in small groups. Once the hands-on component of this activity is completed, the class brainstorms and discusses how blood pressure might affect a person's health. This activity acts as hook for the second lesson in this unit, in which blood pressure is presented in detail, as well as how variances in blood pressure can affect a person's cardiovascular system.