In an activity involving a virtual person, the following body systems can typically be controlled or influenced:
- Pulse
- Oxygen Need
- Food Intake
- Body Temperature
- Blood Pressure
- Glucose
- Blood Delivery
Depending on the specifics of the virtual activity or simulation, all of these systems may be involved, but the most commonly controlled ones would likely include Pulse, Body Temperature, Blood Pressure, and Oxygen Need.
If you need to select only a few, focus on the most directly observable and immediate physiological responses: Pulse, Body Temperature, and Blood Pressure.
For a full selection, I recommend counting all of them unless you have specific instructions to limit your choices.