Answer:
1.SALIVA
2.During chewing, salivary glands in the walls and floor of the mouth secrete saliva (spit), which moistens the food and helps break it down even more. Saliva makes it easier to chew and swallow foods (especially dry foods), and contains enzymes that help begin the digestion of foods.
3. How the Esophagus Works. As a person swallows, food moves from the mouth to the throat, also called the pharynx (1). The upper esophageal sphincter opens (2) so that food can enter the esophagus, where waves of muscular contractions, called peristalsis, propel the food downward
4.Digestion begins in the mouth. The food is ground up by the teeth and moistened with saliva to make it easy to swallow. Saliva also has a special chemical, called an enzyme, which starts breaking down carbohydrates into sugars.
5.Mechanical digestion involves physically breaking the food into smaller pieces. Mechanical digestion begins in the mouth as the food is chewed. Chemical digestion involves breaking down the food into simpler nutrients that can be used by the cells. Chemical digestion begins in the mouth when food mixes with saliva.
Explanation:
