The oral cavity, far better known as the mouth, is the start of the alimentary canal. It has actually three major functions:Digestion – obtain food, preparing it because that digestion in the stomach and tiny intestine.
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Communication – modifies the sound produced in the larynx to create a selection of sounds.Breathing – acts together an waiting inlet in enhancement to the sleep cavity.
In this article, we shall look at the anatomy of the oral cavity – the divisions, contents, and also any clinical correlations.
Divisions that the oral Cavity
The oral cavity spans between the oral fissure (anteriorly – the opening in between the lips), and also the oropharyngeal isthmus (posteriorly – the opening of the oropharynx).
It is split into two components by the upper and reduced dental arches (formed by the teeth and their bony scaffolding). The two departments of the dental cavity space the vestibule and also the mouth cavity proper.
The horseshoe-shaped vestibule is positioned anteriorly. The is the room between the lips/cheeks, and also the gums/teeth.
The vestibule communicates v the mouth appropriate via the an are behind the third molar tooth, and also with the exterior through the oral fissure. The diameter of the oral fissure is regulated by the muscles of facial expression – principally the orbicularis oris.
Opposite the upper second molar tooth, the duct of the parotid gland opens out right into the vestibule, secreting salivatory juices.
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Fig 1 – The two divisions of the oral cavity room the vestibule and oral cavity proper.
The mouth appropriate lies posteriorly come the vestibule. That is bordered by a roof, a floor, and also the cheeks. The tongue filling a large proportion of the cavity the the mouth proper.
The roof that the mouth ideal consists of the hard and soft palates.
The hard palate is found anteriorly. That is a bony plate that separates the sleep cavity from the oral cavity. It is extended superiorly through respiratory mucosa (ciliated pseudostratified columnar epithelium) and also inferiorly by dental mucosa (stratified squamous epithelium).
The soft palate is a posterior continuation of the tough palate. In contrast to the hard palate, it is a muscular structure. It acts together a valve that deserve to lower come close the oropharyngeal isthmus, and also elevate to separate the nasopharynx native the oropharynx.
The cheeks are formed by the buccinator muscle, i beg your pardon is inside wall internally by the oral mucous membrane.
The buccinator muscle contracts to store food between the teeth as soon as chewing, and also is innervated by the buccal branches of the face nerve (CN VII).
The floor that the dental cavity is composed of numerous structures:Muscular diaphragm – comprised the the bilateral mylohyoid muscles. It gives structural assistance to the floor of the mouth, and pulls the larynx forward during swallowing.Geniohyoid muscles – traction the larynx forward during swallowing.Tongue – connected to the floor through the frenulum of the tongue, a fold of oral mucosa.Salivary glands and ducts.
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Fig 2 – frameworks of the oral cavity floor.
Sensory innervation of the dental cavity is supplied by the branches of the trigeminal nerve (CN V).
The tough palate is innervated by the greater palatine and nasopalatine nerves, both of which are branches the the maxillary nerve (CN V2). The soft palate is innervated by lesser palatine nerve, an additional branch that the maxillary nerve.
The floor the the dental cavity receive sensory innervation from the lingual nerve – a branch of the mandibular (V3) division of the trigeminal nerve. The tongue is also innervated by distinct sensory fibres for taste native the chorda tympani, a branch that the facial nerve (CN VII).
The cheeks space innervated by the buccal nerve. It is likewise a branch that the mandibular division of the trigeminal nerve (not to be puzzled with the buccal branches of the facial nerve).
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Fig 3 – The lingual nerve provides sensory innervation to the tongue.