Using different diameter tubes, have the students compare and contrast the change of flow with a smaller tube vs. a larger one. Await them to make the association to the blood vessels. Allow for individual sensitivities. 180 may be high enough for most. Chart the class by teams, allowing for individual preference of volunteering information.
Students can research influencing factors as reports.
Comparing diets before and after the blood pressure studies may be of interest. Students will demonstrate ability to take blood pressure by measuring the two levels of pressure, systolic and diastolic. Students will become more aware of the external and internal influencing factors on blood pressure.