alimentary, elementary

Alimentary or alimentary means concerning nutrition or nourishment--
This food tastes good, but its alimentary value is low.
The alimentary canal includes all of the digestive organs.
The alimentary system removes useful nutrients from the food we eat, and discards the rest.

Elementary or elementary means basic or simple, or composed of the most simple basic parts, literally or figuratively--
He has trouble solving elementary problems; he's not ready for advancement.
"Elementary, my dear Watson."
Elementary school starts at kindergarten and ends at the fifth or sixth grade.

Now that you know that, you can say--
"She is taking the elementary course on the alimentary system."