There are three frames on the left. Use the first pull-down menu to select your category (e.g., Microbiology, Endocrine), then use the second pull-down menu to select your subcategory (e.g., virology, physiology). A list of all the Facts in that category and subcategory appears; click on the Fact you want to see, and voilà – First Aid at your fingertips.

If you want to browse the Facts, use the forward and backward arrows in the toolbar at the top to spin through them; or you can go back to the left frame and jump directly to the Fact you want to see.