Chewing

The act of using the teeth to grind food in the mouth

For the use of chewing gum, see Chewing gum.

A macaque chewing.

Chewing, also known as mastication, is the process by which food is crushed and ground by teeth. It is the first step of digestion and increases the surface area of foods to allow more efficient breakdown by enzymes.

Process

Chewing is a complex process that involves the coordinated action of the jaw, teeth, tongue, and cheeks. The process begins when food is placed in the mouth and the teeth begin to break it down into smaller pieces. The saliva produced by the salivary glands mixes with the food to form a bolus, which can be easily swallowed.

The muscles of mastication, which include the masseter, temporalis, and pterygoid muscles, are responsible for the movement of the jaw during chewing. These muscles are controlled by the trigeminal nerve, which is the fifth cranial nerve.

Functions

Chewing serves several important functions:

• Mechanical digestion: By breaking down food into smaller pieces, chewing increases the surface area available for enzymatic digestion.
• Mixing with saliva: Saliva contains enzymes such as amylase that begin the chemical digestion of carbohydrates.
• Formation of the bolus: Chewing helps to form a cohesive bolus that can be easily swallowed.
• Stimulation of taste: Chewing releases flavors from food, stimulating the taste buds and enhancing the sensory experience of eating.

Chewing in Animals

File:Water buffalo chewing cud - 01.ogv Chewing is not unique to humans; many animals chew their food. Herbivores, such as cows and buffalo, often chew their food multiple times through a process known as rumination, or "chewing the cud." This allows them to break down tough plant materials more effectively.

Chewing Gum

Chewing gum on a sidewalk.

Chewing gum is a popular product that is chewed for flavor and enjoyment rather than nutrition. It is made from a gum base, sweeteners, flavorings, and sometimes softeners. Chewing gum can help to freshen breath and may have some dental benefits, such as increasing saliva flow and reducing plaque.

Health Implications

Chewing has several health implications. Proper chewing can aid in digestion and nutrient absorption. However, excessive or improper chewing can lead to temporomandibular joint disorder (TMJ) and other dental issues.

Also see

• Digestion
• Saliva
• Temporomandibular joint disorder
• Chewing gum
• Mastication (food)