Deer Rumen: Opening up a deer's rumen.Courtesy Kirk MonaEver wondered what's inside the stomach of a deer? For those not afraid of some graphic photos, the Twin Cities Naturalist Blog. has posted photos and descriptions of the four parts of a deer's stomach. Here's a quick overview.

• The Rumen is a fermentation and storage vat. Micro-organisms break down a lot of food in the Rumen so it can be absorbed by the deer but it does not physically break down the food with acid like a human stomach.
• The Reticulum is basically a filter that allows small particles to pass to the Omasum.
• The Omasum acts like a sponge that draws off excess water before food is passed to the next step.
• The Abomasum works like your stomach to break down food with acid so nutrients can be absorbed.

You can see all the photos and read more at Twin Cities Naturalist.