Not sure what you mean by '3 types of digestion', but there are three major food groups (carbohydrates, proteins, and fats), and each has a different method of digestion by the digestive system.
the endangered species act
MHC (major histocompatibility complex)
it is said that the tissues that are responsible for the synthesizing of hormones are the epithelium tissue..
The major and minor salivary glands produce saliva. Saliva has many functions, including lubrication of food, digestion, protection against microorganisms, etc.
The major organ responsible for chemical digestion and absorption of food is the small intestine.
Its the mouth.........cause saliva breaks down some amount of starch into simple sugars. but its not a very major site..............
Salivation is the function that helps digestion by keeping the mouth moist and comfortable when you chew and swallow. The salivary glands secrete saliva for this purpose. The saliva also moistens the food (a physical change), and begins to chemically alter the food with enzymes (a chemical change).
It is primarily the zygomaticus major and risorius muscles that are responsible for a smile, aided in part by the action of the buccinator :)
Saliva pH, in order to rule out major illnesses.
the major part of the chemical digestion is the HCL (hydro chloric acid)