The stomach lining is made up of deep musclar grooves. how do you think these structures the stomach to break down food?

First of all... Let's get this straight. Most stomachs are made of an acid called hydrochloric acid. Hydrochloric acid, as scary as it sounds, is extremely acidic. When food enters our body, the food is broken down into chunks of food, which is later exited through the "You know what". Let's go back to the question. Muscular grooves prevent hydrochloric acid from eating our body.