chew

1 a wad of something chewable as tobacco [syn: chaw, cud, quid, plug, wad]

2 biting and grinding food in your mouth so it becomes soft enough to swallow [syn: chewing, mastication, manduction] v : chew (food); "He jawed his bubble gum"; "Chew your food and don't swallow it!"; "The cows were masticating the grass" [syn: masticate, manducate, jaw]

English

Etymology

ċēowan

Pronunciation

• Rhymes: -uː

Noun

1. A small sweet, such as a taffy, that is eaten by chewing.

   Phillip purchased a bag of licorice chews at the drugstore.

2. informal uncountable Chewing tobacco.

   The school had banned chew and smokes from the school grounds, even for adults.

3. A plug or wad of chewing tobacco; chaw or a chaw.

   The ballplayers sat on the bench watching the rain, glumly working their chews.

   The first time he chewed tobacco, he swallowed his chew and got extremely sick.''

Related terms

• penny chew

Verb

1. To crush with the teeth by repeated closing and opening of the jaws; done to food to soften it and break it down by the action of saliva before it is swallowed.

   Make sure to chew thoroughly, and don't talk with your mouth full!

   The steak was tough to chew as it had been cooked too long.

2. To grind, tear, or otherwise degrade or demolish something with teeth or as with teeth.

   He keep his feed in steel drums to prevent the mice from chewing holes in the feed-sacks.

   The harsh desert wind and sand had chewed the stump into ragged strips of wood.

3. To think about something; to ponder; to chew over.

   The professor stood at the blackboard, chalk in hand, and chewed the question the student had asked.

Synonyms

• bite, chomp, crunch, masticate
• grind, pulverize, rip, shred, tear
• sense think about contemplate, ruminate, mull, muse, ponder

Related terms

• chewing gum
• chew out
• chew over
• chew the cud
• chew up
• chewy

Translations

Mastication or chewing is the process by which food is mashed and crushed by teeth. It is the first step of digestion and it increases the surface area of foods to allow more efficient break down by enzymes. During the mastication process, the food is positioned between the teeth for grinding by the cheek and tongue. As chewing continues, the food is made softer and warmer, and the enzymes in saliva begin to break down carbohydrates in the food. After chewing, the food (now called a bolus) is swallowed. It enters the esophagus and continues on to the stomach, where the next step of digestion occurs.

Cattle and some other animals, called ruminants, chew food more than once to extract more nutrients. After the first round of chewing, this food is called cud.

The chewing cycle

Mastication is a repetitive sequence of jaw opening and closing with a profile in the vertical plane called the chewing cycle. Mastication consists of a number of chewing cycles. The human chewing cycle consists of three phases

1. Opening phase: the mouth is opened and the mandible is depressed.

2. Closing phase: the mandible is raised towards the maxilla.

3. Occlusal or intercuspal phase: the mandible is stationary and the teeth from both upper and lower arches approximate.

Mastication motor program

Mastication is primarily an unconscious act, but can be mediated by higher conscious input. The motor program for mastication is an hypothesized central nervous system function by which the complex patterns governing mastication are created and controlled.

It is thought that feedback from proprioceptive nerves in teeth and the temporomandibular joints govern the creation of neural pathways, which in turn determine duration and force of individual muscle activation (and in some cases muscle fiber groups as in the masseter and temporalis).

The motor program continuously adapts to changes in food type or occlusion http://jn.physiology.org/cgi/content/full/92/2/773.

It is thought that conscious mediation is important in the limitation of parafunctional habits as most commonly, the motor program can be excessively engaged during periods of sleep and times of stress. It is also theorized that excessive input to the motor program from myofascial pain or occlusal imbalance can contribute to parafunctional habits.

In other animals

Chewing is largely an adaptation for mammalian herbivory. Carnivores generally chew very little or swallow their food whole or in chunks, a fact to which many dog and cat owners can attest. This act of gulping food without chewing has inspired the English idiom "wolfing it down".

Ornithopods, a group of dinosaurs including the Hadrosaurids ("duck-bills"), developed teeth analogous to mammalian molars and incisors during the Cretaceous period; this advanced, cow-like dentition allowed the creatures to obtain more nutrients from the tough plant life. This may have given them the advantage needed to usurp the formidable sauropods, who depended on gastroliths for grinding food, from their ecological niches. They eventually became some of the most successful animals on the planet until the Cretaceous–Tertiary extinction event wiped them out.

In machinery

The process of mastication has, by analogy, been applied to machinery. The U.S. Forest Service uses a machine called a masticator to "chew" through brush and timber in order to clear firelines in advance of a wildfire.

Notes

1. http://jn.physiology.org/cgi/content/full/92/2/773 - Influence of age on adaptability of human mastication.

External links

• Neuromuscular dentistry

bawl out, bite, bolus, bullshit, carpet, cavendish, chain-smoke, champ, chat, chaw, chew ass, chew out, chew over, chew the cud, chew up, chewing tobacco, chomp, chump, consider, consume, converse, crunch, crush, cud, cuss out, cut plug, devour, drag, draw, eat, eating tobacco, fid, give a going-over, give hail Columbia, give hell, give the deuce, give what-for, gnash, gnaw, gob, gossip, grind, gum, inhale, inhale snuff, jack up, jaw, lambaste, macerate, mash, masticate, morsel, mouth, mouthful, mumble, munch, navy, navy plug, nibble, nip, palaver, pigtail, ponder, puff, pull, pulp, pulpify, quid, ream, ream ass, ream out, rebuke, reprimand, review, revile, ruminate, scold, scrunch, sit on, smash, smoke, snap, squash, swallow, take snuff, talk, tell off, tobacco juice, tongue-lash, twist, vituperate, wig