digestion
acid
Acid is found in the stomach, because the acid helps in digestion.
lactobacillus
it decreases acidity and helps in digestion.
Under the stomach lies the small intestines.
They have rocks in them because it helps with digestion in their stomach.
The Human stomach (also known as 'the belly') is an internal system which helps in the digestion of food.
Amylase
Yes, enzymes are present in the stomach. The main enzyme in the stomach is pepsin, which helps break down proteins into smaller peptides for digestion. These enzymes are secreted by the stomach lining to aid in the digestion process.
There is the small intestine, stomach, and the mouth, and that is all that i can think of. Hope this answer helps you people out there looking for three of the organs for mechanical digestion. But if not....... well that sucks for you.
It's a form of physical digestion, I assume its the substance inside your stomach, i.e liquid in the central region.