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It represents the first part of digestive tube

It extends from the oral fissure ( anterior opening between lips) and ends at the oropharyngeal isthmus (posterior opening of the oropharynx)

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Apart from the teeth the following structures are the basic components

Tongue,

Lips,Cheek

Palate (hard and soft)

Uvula,

Floor of the mouth

Oropharynx

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The oral cavity is lined throughout with mucus membrane consisting of stratified squamous epithelium containing small mucus secreting glands.

The part of the mouth between gums and cheeks is a called the vestibule, and the remaining part is called the oral cavity.

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What are the boundaries of the oral cavity 3 minutes

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Anteriorly: lower and upper lip

Posterior -Oropharyngeal isthmus

Laterally: cheeks.

Roof: soft and hard palate

Floor: contains muscles

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The floor of the oral cavity consist of the following

Muscular diaphragm – bilateral mylohyoid muscles.

Geniohyoid muscle – pulls the larynx forward during swallowing.

Tongue – connected to the floor by frenelum of the tongue

Salivary glands and ducts.

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Lips

They are covered externally by skin and internally by mucous membrane; the junction between skin and mucous membrane is highly sensitive.

When lips are closed, line of contact is oral fissure.

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Cheeks

Are formed in large part by buccinator muscles covered by adipose tissue

They form the lateral boundaries of the oral cavity, they are continuous with lips and lined by mucous membrane.

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They contain mucus secreting glands which are placed between mucous membrane and buccinator muscle. Their ducts open opposite the last molar teeth

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Consist of portions of four bones, two maxillae and two palatine bones

Soft palate forms partition between the mouth and nasopharynx and is made of muscles arranged in an arch

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Suspended from midpoint of the posterior border of the arch is the uvula

The opening from the mouth into the oropharynx is called fauces

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This is a large bundle of skeletal muscles on the floor of the mouth that manipulates food for chewing and swallowing (deglutition).

It contains the root, tip and the body.

Lingual frenulum anchors the tongue to the floor of the mouth

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Much of the upper surface of the tongue is covered by papillae and taste buds.

The tongue, with its wide variety of possible movements, assists in forming the sounds of speech.

It is sensitive and kept moist by saliva, and is richly supplied with nerves and blood vessels to help it move

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The tongue has two sides

The ventral (lower surface) and the dorsum (upper surface)

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The dorsum of the tongue can be divided into two parts

an oral part (anterior two-thirds of the tongue) that lies mostly in the mouth

a pharyngeal part (posterior third of the tongue), which faces backward to the oropharynx

The two parts are separated by a V-shaped groove, which marks the sulcus terminalis (or terminal sulcus).

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The oral part of the tongue is covered with small bumpy projections called papillae. There are four types of papillae:

filiform

fungiform

circumvallate

foliate

All papillae except the filiform have taste buds on their surface.

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The circumvallate are the largest of the papillae.

There are 8 to 14 circumvallate papillae arranged in a V-shape in front of the sulcus terminalis, creating a border between the oral and pharyngeal parts of the tongue

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The underside of the tongue is covered with a smooth mucous membrane, with a fold (the lingual frenulum) in the center.

If the lingual frenulum is too taut or too far forward, it can impede motion of the tongue, a condition called ankyloglossia.

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The upper side of the posterior tongue (pharyngeal part) has no visible taste buds, but it is bumpy because of the lymphatic nodules lying underneath.

These follicles are known as the lingual tonsil.

The human tongue can detect four basic taste components: sweet, sour, salty and bitter

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The tongue receives its blood supply primarily from the lingual artery, a branch of the external carotid artery.

The floor of the mouth also receives its blood supply from the lingual artery.

There is also secondary blood supply to the tongue from the tonsillar branch of the facial artery and the ascending pharyngeal artery.

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There are two types of muscles forming the tongue: intrinsic and extrinsic muscles.

Intrinsic muscles: They originate and insert in the tongue itself.

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Extrinsic muscles: Are muscles that insert into the tongue but originate from other structures such as hyoid bone.

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There are four intrinsic muscles of the tongue

Vertical muscles

Transerve muscles

Superior longitudinal muscles

Inferior longitudinal muscles

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There are four extrinsic muscles of the tongue

Genioglossus

Hyoglossus

Styloglossus

Palatoglossus

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What are the functions of the oral cavity?

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Digestion – receives food, preparing it for digestion in stomach and small intestine

Communication – modifies the sound produced in the larynx to create a range of sounds

Breathing – act as an air inlet in addition to the nasal cavity

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