Oral Cavity

Mouth

This article is about the anatomical structure. For other uses, see Mouth (disambiguation).

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Mouth
Head and neck.
A closed human female mouth
Latin	os, cavitas oralis
MeSH	Oral+cavity

The mouth is the first portion of the alimentary canalthat receives food and saliva.^[1] The oral mucosa is themucous membrane epithelium lining the inside of the mouth.

In addition to its primary role as the beginning of the digestive system, in humans the mouth also plays a significant role in communication. While primary aspects of the voice are produced in the throat, thetongue, lips, and jaw are also needed to produce the range of sounds included in human language. Another non-digestive function of the mouth is its role in secondary social and/or sexual activity, such askissing.

The mouth is normally moist, and is lined with amucous membrane. The lips mark the transition from mucous membrane to skin, which covers most of thebody.

Contents  [hide] 1 In Humans 1.1 Mouth cavity 1.2 Function 1.3 Cultural aspects 1.4 Development 2 In non-human animals 3 See also 4 References 5 External links

[edit]In Humans

[edit]Mouth cavity

Illustration of the inside of a human mouth. Cheeks have been cut and lips pulled back for an unobstructed view.

The first space of the mouth is the mouth cavity, bounded laterally and in front by the alveolar arches (containing theteeth), and posteriorily by the isthmus of the fauces. The oral cavity is also known as the mouth which swallows food and drinks that then go down the esophagus and into the stomach.

[edit]Function

The mouth plays an important role in sucking (it is part of the sucking apparatus), facial expression, eating, drinking, and breathing. Infants are born with a sucking reflex, by which they instinctively know to suck for nourishment using their lips and jaw.

[edit]Cultural aspects

According to Western etiquette, the mouth is kept closed, especially when chewing.

Lips can be adorned with lipstick or lip gloss, although in most cultures this is typically only practiced by females. Both men and women, however, apply lip balm in order to soothe chapped or dry lips.

Piercings in or around the mouth have been made popular by younger generations, including those on the lip or tongue. The uvula piercing, while increasing in popularity, remains relatively rare.

[edit]Development

The philtrum is the vertical groove in the upper lip, formed where the nasomedial and maxillaryprocesses meet during embryo development. When these processes fail to fuse fully, a hare lip and/orcleft palate can result.

The nasolabial folds are the deep creases of tissue that extend from the nose to the sides of the mouth. One of the first signs of age on the human face is the increase in prominence of the nasolabial folds.

[edit]In non-human animals

Alligators are known for their large mouths and sharp teeth

Some animal phyla, including vertebrates, have a completedigestive system, with a mouth at one end and an anus at the other. Which end forms first in ontogeny is a criterion used to classify animals into protostome anddeuterostome. The first space of the mouth is the mouth cavity, bounded laterally and in front by the alveolar arches (containing the teeth), and posteriorly by the isthmus of the fauces.^[1]