| Human mouth | |
|---|---|
 Photograph of the closed mouth of a male | |
 Head and neck | |
| Details | |
| Identifiers | |
| Latin | os, oris[1] |
| TA98 | A01.1.00.010 |
| TA2 | 119 |
| Anatomical terminology | |
Inhuman anatomy, themouth is the first portion of thealimentary canal that receivesfood and producessaliva.[2] Theoral mucosa is the mucous membraneepithelium lining the inside of the mouth.
In addition to its primary role as the beginning of thedigestive system, the mouth also plays a significant role incommunication. While primary aspects of thevoice are produced in thethroat, thetongue,lips, andjaw are also needed to produce the range of sounds included inspeech.
The mouth consists of two regions, thevestibule and theoral cavity proper. The mouth, normally moist, is lined with amucous membrane, and contains theteeth. The lips mark the transition from mucous membrane toskin, which covers most of thebody.
The mouth consists of two regions: the vestibule and the oral cavity proper. The vestibule is the area between the teeth, lips and cheeks.[3] The oral cavity is bounded at the sides and in front by thealveolar process (containing theteeth) and at the back by theisthmus of the fauces. Its roof is formed by thehard palate. The floor is formed by themylohyoid muscles and is occupied mainly by the anterior two-thirds of thetongue. Amucous membrane – theoral mucosa, lines the sides and under surface of the tongue to thegums, and lines the inner aspect of the jaw (mandible). It receives secretions from thesubmandibular andsublingualsalivary glands. The posterior border of the oral cavity (ie, junction between the oral cavity and theoropharynx) includes the junction of thehard palate and thesoft palate superiorly, thecircumvallate papillae of thetongue inferiorly, and theretromolar trigone.
Thelips come together to close the opening of the mouth, forming a line between the upper and lower lip. Infacial expression, thismouth line is iconically shaped like an up-openparabola in asmile, and like a down-open parabola in afrown. Adown-turned mouth means a mouth line forming a down-turned parabola, and when permanent can be normal. Also, adown-turned mouth can be part of the presentation ofPrader–Willi syndrome.[4]
The teeth and theperiodontium (thetissues that support the teeth) are innervated by themaxillary andmandibular nerves – divisions of thetrigeminal nerve. Maxillary (upper) teeth and their associatedperiodontal ligament are innervated by the superior alveolar nerves, branches of the maxillary division, termed theposterior superior alveolar nerve,anterior superior alveolar nerve, and the variably presentmiddle superior alveolar nerve. These nerves form thesuperior dental plexus above the maxillary teeth. The mandibular (lower) teeth and their associated periodontal ligament are innervated by theinferior alveolar nerve, a branch of the mandibular division. This nerve runs inside the mandible, within theinferior alveolar canal below the mandibular teeth, giving off branches to all the lower teeth (inferior dental plexus).[5][6] Theoral mucosa of the gingiva (gums) on thefacial (labial) aspect of the maxillaryincisors,canines andpremolar teeth is innervated by the superior labial branches of theinfraorbital nerve. The posterior superior alveolar nerve supplies the gingiva on the facial aspect of the maxillarymolar teeth. The gingiva on thepalatal aspect of the maxillary teeth is innervated by thegreater palatine nerve apart from in the incisor region, where it is thenasopalatine nerve (long sphenopalatine nerve). The gingiva of thelingual aspect of the mandibular teeth is innervated by the sublingual nerve, a branch of thelingual nerve. The gingiva on the facial aspect of the mandibular incisors and canines is innervated by themental nerve, the continuation of the inferior alveolar nerve emerging from themental foramen. The gingiva of the buccal (cheek) aspect of the mandibular molar teeth is innervated by thebuccal nerve (long buccal nerve).[7]
Thephiltrum is the vertical depression formed between thephiltral ridges between the upper lip and the nasal septum, formed where thenasomedial andmaxillary processes meet duringembryo development. When these processes fail to fuse fully, acleft lip,cleft palate, or both can result.
Thenasolabial 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.
The mouth plays an important role ineating,drinking, and speaking.Mouth breathing refers to the act of breathing through the mouth (as a temporary backup system) if there is an obstruction tobreathing through the nose, which is the designated breathing organ for the human body.[8]
Infants are born with asucking reflex, by which theyinstinctively know to suck for nourishment using their lips andjaw.The mouth also helps inchewing andbiting food.
For some disabled people, especially many disabled artists, who through illness, accident or congenital disability have lost dexterity, their mouths take the place of their hands, when typing, texting, writing, makingdrawings,paintings and other works of art by maneuvering brushes and other tools, in addition to the basic oral functions.Mouth painters hold the brush in their mouth or between their teeth and maneuver it with their tongue and cheek muscles, but mouth painting can be strenuous for neck and jaw muscles since the head has to perform the same back and forth movement as a hand does when painting.[9][10]
Amale mouth can hold, on average, 71.2 ml (2.51 imp fl oz; 2.41 US fl oz), while afemale mouth holds 55.4 ml (1.95 imp fl oz; 1.87 US fl oz).[11]
Media related tohuman mouths at Wikimedia Commons
Quotations related tomouths at Wikiquote
