For Your Biologists: BioDigitalHuman.COM [Standard Version: Free]
Link: Bio Digital Human
Login: Enter E-Mail address and password [not verified]
Select which gender you want to work with and which structures you want to see by sliding buttons to the right in the slider menu and sub-menus [bottom right]
Clicking the stethoscope in this menu reveals a list of conditions that can affect the human body [organised A - Z]
Other features available in the standard version:
Transparency Mode, Isolate Mode, Single Pick, Multi Pick and Dissect.
Left click and hold to rotate the model in three dimensions and roll the mouse wheel to zoom in/out.