Mastication or chewing is the first mechanical process in the gastrointestinal tract, by which the food substances are torn or cut into small particles and crushed or ground into a soft bolus.
Three stages have been identified:
Stage I: involves transport from the front of the mouth to the premolars and is characterized by low amplitude jaw movements. It is placing the food in an advantageous position with regard to the teeth.
Stage II: reduces particles size. By reducing the size of food particles, the surface are is increased for enzyme activity.
Stage III: pre-swallowing and the food moves to the back of the tongue by tongue-palate interaction
Significances of mastication:
*Breakdown of foodstuffs into smaller particles (comminution process)
*Mixing of saliva with food substances thoroughly
*Lubrication and moistening of dry food by saliva, so that the bus can be easily swallowed
*Appreciation of taste of the food
During cutting process, the food is comminuted by the action of the teeth into particles with size typically a few millimeters. The incisors provide a strong cutting action, while the posteriorly placed molars grind the ingested food.
As soon as food is placed in the mouth, saliva is secreted in response to mechanical stimulation and to the taste qualities of the food. Saliva mixes with food, acting as lubricant during the masticatory process.
Mixing with saliva also affects bolus formation, thus the decision for swallowing.
Mastication stage process
