This is a ringing that sets in after excessive noise exposure, such as in a rock concert (being too near the speakers) or the explosion of a firecracker. This excessive noise can cause injury to the ear, causing the ringing. The tinnitus will usually clear up on its own, and will last anywhere from minutes to hours.
Mechanical digestion is the actual physical break down of food into smaller pieces. One example of this is mastication (chewing) which occurs in the mouth by the teeth, which act to cut and grind food into smaller pieces. This makes them easier to later digest as it increases the SA of the food molecules.
Digestion refers to the breakdown of food into smaller components that can be absorbed into the bloodstream. This digestion or catabolism is divided into two types â the mechanical digestion of food that occurs in the mouth when it is physically broken up into smaller pieces and the chemical digestion that occurs in the gastrointestinal tract when the food is broken down into small molecules by digestive enzymes.