part of part of ruminant forestomach omasum https://upload.wikimedia.org/wikipedia/commons/2/2b/Abomasum_(PSF).png The third stomach of ruminants, situated on the right side of the abdomen at a higher level than the fourth stomach and between this latter and the second stomach, with both of which it communicates. From its inner surface project large numbers of leaves or folia, each of which possesses roughened surfaces. In the center of each folium is a band of muscle fibers which produces a rasping movement of the leaf when it contracts. One leaf rubs against those on either side of it, and large particles of food material are ground down between the rough surfaces, preparatory to further digestion in the succeeeding parts of the alimentary canal. (Black's Veterinary Dictionary, 17th ed). GAID:1242 NCIT:C98766 omasal UMLS:C0028972 MESH:D009851 UBERON:0007362 BTO:0000348 omasum Wikipedia:Omasum reticulorumen stomach non-glandular region