The
mouth,
buccal cavity, or
oral cavity is the first portion of the alimentary canal that receives food and begins digestion by mechanically breaking up the solid food particles into smaller pieces and mixing them with
salivaSaliva is the watery and usually frothy substance produced in the mouths of humans and most other animals. Saliva is produced in and secreted from the salivary glands...
. The
oral mucosaThe oral mucosa is the mucous membrane epithelium of the mouth. It can be divided into three categories.*Masticatory mucosa - keratinized stratified squamous epithelium, found on the dorsum of the tongue, hard palate and attached gingiva....
is the
mucous membraneThe mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs. It is at several places continuous with skin: at the nostrils, the...
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 Communication is a process of transferring information from one entity to another. Communication processes are sign-mediated interactions between at least two agents which share a repertoire of signs and semiotic rules. Communication is commonly defined as "the imparting or interchange of...
. While primary aspects of the
voiceVoice may refer to:* Human voice* Voice control or voice activation* Writer's voice* Voice acting* Voice vote* Voice message* Voice , a 2005 South Korean filmIn music:* Vocal music** The human voice in singing...
are produced in the
throatIn anatomy, the throat is the anterior part of the neck, in front of the vertebral column. It consists of the pharynx and larynx. An important feature of the throat is the epiglottis, a flap which separates the esophagus from the trachea and prevents inhalation of food or drink.The throat...
, the
tongueThe tongue is a muscle on the floor of the mouth that manipulates food for chewing and swallowing . It is the primary organ of taste, as much of the upper surface of the tongue is covered in papillae and taste buds. A secondary function of the tongue is speech, in which the organ assists...
,
lipLips are a visible body part at the mouth of humans and many animals. Lips are soft, movable, and serve as the opening for food intake, as an erogenous organ used in kissing and other acts of intimacy, as a tactile sensory organ, and in the articulation of speech.-Anatomical basics of the human...
s, and
jawThe mandible or inferior maxillary bone forms the lower jaw and holds the lower teeth in place. It also refers to both the upper and lower sections of the beaks of birds; in this case the "lower mandible" corresponds to the mandible of humans while the "upper mandible" is functionally equivalent...
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 as
kissA kiss is the touching of one person's lips to another place, which is used as an expression of affection, respect, greeting, farewell, good luck, romantic affection or sexual desire...
ing. The physical appearance of the mouth and lips play a part in defining sexual attractiveness.
The mouth is normally moist, and is lined with a
mucous membraneThe mucous membranes are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. They line various body cavities that are exposed to the external environment and internal organs. It is at several places continuous with skin: at the nostrils, the...
. The lips mark the transition from mucous membrane to
skinThe skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system made up of multiple layers of mesodermal tissue, and guards the underlying muscles, bones, ligaments and internal organs. Skin of a different nature exists in amphibians, reptiles, birds...
, which covers most of the body.
Mouth Cavity
The first space of the mouth is the mouth cavity, bounded laterally and in front by the alveolar arches (containing the teeth), and posteriorily by the
isthmus of the faucesThe oropharyngeal isthmus lies between the soft palate and the root of the tongue, and is bounded on both sides by the palatoglossal arches. Each palatoglossal arch runs downwards, laterally and forwards, from the soft palate to the side of the tongue...
. The oral cavity is also known as the mouth which swallows food and drinks that then go down the esophagus and into the stomach.
Function
The mouth plays an important role in
speechSpeech is the human faculty of speaking.It may also refer to:* Public speaking, the process of speaking to a group of people* Manner of articulation, how the body parts involved in making speech are manipulated...
(it is part of the
vocal apparatusVocal apparatus or vocal organs is a term used in phonetics to designate all parts of human anatomy that can be used to produce speech. This includes the lips, tongue, teeth, hard and soft palates, uvula, larynx, lungs, etc.-See also:...
),
facial expressionA facial expression results from one or more motions or positions of the muscles of the face. These movements convey the emotional state of the individual to observers. Facial expressions are a form of nonverbal communication...
,
eatingEating is the process of ingesting food to provide for an animal's nutritional needs, particularly for energy and growth. All animals must eat organisms in order to survive: carnivores eat other animals, herbivores eat plants, and omnivores consume a mixture of both; see feeding.-Eating...
,
drinkA drink, or beverage, is a liquid which is specifically prepared for human consumption. In addition to filling a basic human need, beverages form part of the culture of human society.-Water:...
ing and
breathingBreathing is the process that takes oxygen in and carbon dioxide out of the body. Aerobic organisms require oxygen to release energy via respiration, in the form of the metabolism of energy-rich molecules such as glucose...
.
InfantAn infant or baby is the term used to refer to the very young offspring of humans and other primates.-Infant:The term infant derives from the Latin word infans, meaning "unable to speak."...
s are born with a sucking reflex, by which they
instinctInstinct is the inborn complex behavior of a living organism that is not learned. Since the 1910 NY Times article , most scientific journals consider the term outdated although it remains popular among the general public and a number of scientists...
ively know to suck for nourishment using their lips and
jawThe jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of...
.
Cultural aspects
According to western
etiquetteEtiquette is a code of behavior that delineates expectations for social behavior according to contemporary conventional norms within a society, social class, or group...
, the mouth is kept closed, especially when chewing.
Lips can be adorned with
lipstickLipstick is a cosmetic product containing pigments, oils, waxes, and emollients that applies color and texture to the lips. There are many varieties of lipstick.Women in the ancient Indus Valley Civilization applied lipstick to their lips for face decoration...
or
lip glossLip gloss is a cosmetic product used primarily to give lips a mildly glossy lustre and sometimes subtle color. It is distributed as a liquid or a soft solid...
, although in most cultures this is typically only practiced by females. Both men and women, however, apply
lip balmLip balm or lip salve is a form of make-up topically applied to the lips of the mouth to relieve chapped or dry lips, angular cheilitis or stomatitis, and cold sores. Lip gloss is similar in the fact that it is topically applied to the lips of the mouth, but generally has only cosmetic properties...
in order to soothe chapped or dry lips.
Piercings in or around the mouth have been made popular by the younger generations. Piercings on the lip or tongue are not uncommon. The
uvula piercingA uvula piercing is a body piercing through the uvula. This is a rare piercing, and although the procedure is relatively simple many piercers may refuse to perform it. The uvula is an extremely vascular piece of tissue and heals very rapidly...
is also making a greater appearance, though it still remains a relatively rare piercing and there are still many piercers who refuse to do it.
Development
The
philtrumThe philtrum , also known as the infranasal depression, is the vertical groove in the upper lip, formed where the nasomedial and maxillary processes meet during embryonic development....
is the vertical groove in the upper lip, formed where the nasomedial and
maxillaThe maxilla is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible , which is also a fusion of two halves at the mental symphysis. Sometimes , the maxilla is sometimes called "upper maxilla", with the mandible being the "lower maxilla"...
ry processes meet during
embryoAn embryo is a multicellular diploid eukaryote in its earliest stage of development, from the time of first cell division until birth, hatching, or germination...
developmentEmbryogenesis is the process by which the embryo is formed and develops. It starts with the fertilization of the ovum which, after fertilization, is referred to as a zygote. The zygote undergoes rapid mitotic divisions with no significant growth and cellular differentiation, leading to...
. When these processes fail to fuse fully, a hare lip and/or cleft 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.
In animals
Some animal
phylaIn biology, a phylum ["Phylum" is adopted from the Greek phylai, the clan-based voting groups in Greek city-states.] is a taxonomic rank below Kingdom and above Class...
, including
vertebrateVertebrates are members of the subphylum Vertebrata, chordates with backbones or spinal columns. About 58,000 species of vertebrates have been described. Vertebrata is the largest subphylum of chordates, and contains many familiar groups of large land animals. Vertebrates comprise cyclostomes, bony...
s, have a complete digestive system, with a mouth at one end and an anus at the other. Which end forms first in
ontogenyOntogeny describes the origin and the development of an organism from the fertilized egg to its mature form...
is a criterion used to classify animals into
protostomeProtostomia are a clade of animals. Together with the deuterostomes and a few smaller phyla, they make up the Bilateria, mostly comprising animals with bilateral symmetry and three germ layers...
and
deuterostomeDeuterostomes are a superphylum of animals. They are a subtaxon of the Bilateria branch of the subregnum Eumetazoa, and are opposed to the protostomes...
. 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.
See also
- Head and neck anatomy
Head and neck anatomy focuses on the structures of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat...
- Mouth breathing
Mouth breathing refers to the state of inhaling and exhaling through the mouth.A healthy individual normally breathes through the nose while resting or doing light exercise, and breathes simultaneously through both the nose and mouth during vigorous aerobic exercise, in order to supply sufficient...
- Index of oral health and dental articles
- Outline of dentistry
- Tonsillolith
A tonsillolith is a piece of calcareous matter which forms in the rear of the mouth, in the crevasses of the palatine tonsils ....