1) Saliva moistens food for easier swallowing, saliva lysozyme kills bacteria, saliva amylase breaks down starch.
2) The unconditioned reflex of salivation occurs when food enters the mouth.
3) The conditioned reflex of salivation occurs when the sight of food, the smell of food, the sounds of the dining room, when the time for a meal comes, when talking about food.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.