The digestive system is designed to convert the foods eaten on a daily basis into materials the body can use. To do this, a series of chemical and mechanical processes work to gradually alter food materials into a molecular form. The processes that take place in the mouth mark the first transition stage within the digestive system.
Digestion takes place within the digestive tract--a long, continuous canal that starts at the mouth and ends at the anus. The pharynx, oesophagus, stomach, and small and large intestines sit between these two openings. Each area within the digestive tract involves some sort of chemical or mechanical process that's designed to prepare food materials for the next stage in the process. The teeth, tongue and salivary glands inside the mouth handle the initial breakdown of food into smaller, softer pieces.
According to MA Exam Help, the mouth's first role within the digestion process makes it possible for foods to be ingested by the body. Once ingested, the mouth then prepares food materials for absorption by the digestive tract, which leads to the eventual metabolism of food molecules by individual cells throughout the body. The mouth carries out a mechanical process through chewing motions that break down food materials, as enzyme secretions work to moisten and loosen food fragments.
The mouth's ability to chew and break down foods relies on the physical structures that make-up the mouth, which is also known as the oral cavity according to MA Exam Help. The lips, cheeks and palate all form an enclosure that holds food in place while the teeth and tongue move food materials about. The lips, cheeks and palate also contain nerve endings that act as sensors in determining food temperatures and textures. In effect, the longer the mouth engages in mechanical activities the easier it'll be for the remainder of the digestive tract to absorb and process food materials for the body's use.
Chemical digestion in the mouth is managed by the salivary glands. In total, three pairs of glands work together to produce saliva, which alters the chemical structure of ingested food materials. According to MA Exam Help, the parotid, submandibular and sublingual glands all play a part in producing saliva secretions inside the mouth. These glands are located on the floor of the mouth and on the tongue. The resulting mixture consists of mucus, water and an enzyme called amylase. These secretions are designed activate the taste buds as well as moisten and dissolve foods.
According to MA Exam Help, the tongue, teeth and palate each play a role in carrying out the mechanical and chemical processes that take place inside the mouth. Indentations called papillae line the surface of the tongue. The papillae contain the taste buds and also create a friction surface for food materials. The arrangement of the teeth places the sharpest ones (incisors) up front for biting and tearing purposes. Next to the incisors sit the cuspids, which have cone-like shapes designed for grabbing onto food pieces. Crushing and grinding functions are handled by the flat-surfaced molar teeth that sit in the back of the mouth. Once these activities are completed, the palate moves food materials from the mouth into the pharynx portion of the digestive canal.