dentistry: Associated Structure of the Oral Cavity

• The tongue is a muscular organ in the mouth.
• The tongue is covered with moist, pink tissue called mucosa.
• Tiny bumps called papillae give the tongue its rough texture.
• Thousands of taste buds cover the surfaces of the papillae.
• Taste buds are collections of nerve-like cells that connect to nerves running into the brain.
• The tongue is anchored to the mouth by webs of tough tissue and mucosa.
• The tether holding down the front of the tongue is called the frenum.
• In the back of the mouth, the tongue is anchored into the hyoid bone.
• The tongue is vital for chewing and swallowing food, as well as for speech.
• The tongue is a muscular hydrostat that forms part of the floor of the oral cavity.
• The left and right sides of the tongue are separated by a vertical section of fibrous tissue known as the lingual septum.
• This division is along the length of the tongue save for the very back of the pharyngeal part and is visible as a groove called the median sulcus.
• The human tongue is divided into anterior and posterior parts by the terminal sulcus which is a V-shaped groove.
• The apex of the terminal sulcus is marked by a blind foramen, the foramen cecum, which is a remnant of the median thyroid diverticulum in early embryonic development.
• The anterior oral part is the visible part situated at the front and makes up roughly two-thirds of the length of the tongue.
• The posterior pharyngeal part is the part closest to the throat, roughly one-third of its length.
• These parts differ in terms of their embryological development and nerve supply.
• The tongue has many nerves that help detect and transmit taste signals to the brain.
• Lingual papillae (singular papilla) are the small, nipple-like structures on the upper surface of the tongue that give it its characteristic rough texture.
• The four types of papillae on the human tongue have different structures and are accordingly classified as circumvallate (or vallate), fungiform, filiform, and foliate.
• All except the filiform papillae are associated with taste buds.
• Filiform papillae are the most numerous of the lingual papillae.
• They are fine, small, cone-shaped papillae covering most of the dorsum of the tongue.
• Filiform papillae are responsible for giving the tongue its texture and are responsible for the sensation of touch.
• Unlike the other kinds of papillae, filiform papillae do not contain taste buds.
• Filiform papillae cover most of the front two-thirds of the tongue's surface.
• Filiform papillae appear as very small, conical or cylindrical surface projections, and are arranged in rows which lie parallel to the sulcus terminalis.
• At the tip of the tongue, these rows become more transverse.
• Fungiform papillae are club shaped projections on the tongue, generally red in color.
• Fungiform papillae are found on the tip of the tongue, scattered amongst the filiform papillae but are mostly present on the tip and sides of the tongue.
• Foliate papillae are covered with epithelium, lack keratin and are softer, and bear many taste buds.
• The core of connective tissue is located in the center of the tongue.
• The two parotid glands are major salivary glands wrapped around the mandibular ramus in humans.
• The circumvallate papillae are situated on the surface of the tongue immediately in front of the foramen cecum and sulcus terminalis, forming a row on either side; the two rows run backward and medially, and meet in the midline.
• Taste buds are located on the upper surface of the tongue and can distinguish the five tastes: sweet, sour, bitter, salty, and umami.
• The circumvallate papillae contain taste buds along the sides of whorls and are located in the posterior third of the tongue in the shape of a V.
• The parotid glands are located posterior to the mandibular ramus and anterior to the mastoid process of the temporal bone.
• Humans have three paired major salivary glands (parotid, submandibular, and sublingual) as well as hundreds of minor salivary glands.
• In mucous secretions the main protein secreted is mucin, which acts as a lubricant.
• The foliate papillae appear as a series of red colored, leaf–like ridges of mucosa.