Oral Mucous Membrane: Structure, Function, And Specialized Regions

Oral Mucous Membrane: Structure, Function, And Specialized Regions

Write about the specialized mucosa of the oral cavity.
Answer:

Specialized mucosa:

• The mucous membrane covering the dorsum of the tongue is called a specialized mucosa.
• It is covered by functionally highly extensible masticatory mucosa.

Dorsum of the tongue:

• It is rough and irregular.
• It is covered by a stratified squamous keratinized epithelium.
• It is divided by the V-shaped groove called sulcus terminals into:

1. Anterior two-thirds- the body of the papillary part.

• Mucosa is derived from the first pharyngeal arch.
• It is supplied by the lingual nerve.

2. Posterior one-third-base or lymphatic part.

• Derived from the third pharyngeal arch.
• It is supplied by the glossopharyngeal nerve.

Fungiform papillae:

• They are scattered between the numerous filiform papillae at the tip of the tongue.
• They are red, smooth, round structures.
• They are covered by thin, nonkeratinized epithelium.
• They have a rich capillary network.
• They contain one to three taste buds only on their dorsal surface.

Filiform Papillae:

• They are fine-pointed, cone-shaped papillae covering the anterior part of the tongue.
• Covered by a thick keratinized epithelium, containing a core of connective tissue.
• They form a tough, abrasive surface.
• They do not contain taste buds.
• They are involved in compressing and breaking food when the tire tongue is opposed to the tire hard palate.

Foliate papillae:

• They are leaflike papillae present on the lateral margins of the posterior part of the tongue.
• They consist of 4-11 parallel ridges separated by deep grooves.
• They contain few taste buds.
• They are more frequent in mammals.

Circumvallate papillae:

• They are 8-12 large structures present just anterior to the sulcus terminalis.
• They are surrounded by a deep, circular groove for the opening of ducts of minor salivary glands.
• They contain a connective tissue core covered by a keratinized epithelium.
• Taste buds are present on its lateral surface.
• Its free surface shows numerous secondary papillae.
• They do not protrude above the surface of the tongue.
• Their function is to wash out the soluble food elements.
• They are also the main source of salivary lipase.

Posterior one-third of the tongue:

• It contains round or oval prominences – lingual follicles.
• Each of these has one or more lymph nodules.
• Lingual follicles have a small central pit called a lingual crypt lined with stratified squamous epithelium.
• Ducts of small mucous lingual glands open into the lingual crypt.
• The lingual follicles together form the lingual tonsil.