Welcome to Circulation. This unit was the first one developed for the Human Biology Curriculum. As we experimented with different approaches, formats, and styles, this unit changed many times. It has also been the subject of many demonstrations at meetings of professional educators such as the National Middle School Association and the National Science Teacher Association, and it has been field tested more than any other unit in the curriculum. For us this unit is an old favorite.
Circulation is an excellent example of what we are trying to achieve in the Human Biology Curriculum. Student interest is stimulated because the science content is relevant to them. They can all relate to their hearts, and many have been touched directly or indirectly by someone suffering from and even dying from a heart attack. Because this material captures their interest, we can achieve a much higher level of science coverage than is normally achieved in a middle grades life science course-and students do not find it difficult! Most importantly, the material is interdisciplinary and provides opportunities for team teaching. Mathematics is involved in calculating blood volumes, blood flow rates, heart rates, and diameter/resistance calculations. Physical sciences are touched upon through considerations of pressure, resistance, flow relationships. Health is obviously a major focus with material on diet, smoking, exercise, heart disease prevention, and CPR. You can teach this unit alone, or you can join with your colleagues in creating a team. At one school teachers formed a team and then combined this unit with the ones on breathing and digestion/nutrition to create an overall theme of physical fitness. This was a huge success with the students.
As with every unit, I must emphasize the importance and the value of the activities. Learning by doing is the most effective form of education. This year I used one of the activities-the Amazing Pump--as a demonstration in my undergraduate physiology class at Stanford. That was the one aspect of the class that got the most frequent and positive comments on the students' course review survey. Just a discussion of pressure, vessel compliance, and flow would not have received even passing mention. The activities for this unit are very diverse and rich. A favorite one with students is the making of a stethoscope and recording measurements of their heart rates. Dissecting a cow heart is also a hit. There are many opportunities in this unit to have a great deal of fun in the course of learning about the heart and circulation.
I hardly need mention that this unit may do more to promote the health of your students than any other activity they might be engaged with. You might think it morbid to point out that one-third of them will eventually die of heart failure. Students at this age have a great sense of invulnerability, but that fact might have an impact. Most students get very involved in the discussions of heart disease prevention stimulated by the unit.
Please let us know about your experience with this Circulation unit.
H. Craig Heller
Chair, Department of Biological Sciences, Stanford University