TongueTongue

The tongue isThe tongue is fleshy, fleshy, movable, muscular organ, movable, muscular organ, attached in most attached in most vertebrates to the floor of vertebrates to the floor of the mouth, that is the the mouth, that is the principal organ of taste, principal organ of taste, an aid in chewing and an aid in chewing and swallowing, and, in swallowing, and, in humans, an important humans, an important organ of speechorgan of speech. .

Regions of tongueRegions of tongue

Blade: The blade is the region of the tongue anterior to Blade: The blade is the region of the tongue anterior to the frenulum.the frenulum.Body: The body extends from the circumvallate papillae Body: The body extends from the circumvallate papillae to the frenulum, the anterior part of the genioglossus to the frenulum, the anterior part of the genioglossus muscle. The body is the largest segment and it muscle. The body is the largest segment and it convenient to arbitrarily separate the body into an convenient to arbitrarily separate the body into an anterior and posterior part. The anterior and posterior part. The anterior bodyanterior body is beneath is beneath the hard palate, the the hard palate, the posterior bodyposterior body lies beneath the soft lies beneath the soft palate.palate.Base or root : Base or root : The base, or root, is that part of the The base, or root, is that part of the tongue posterior to the sulcus terminalis, the line of tongue posterior to the sulcus terminalis, the line of circumvallate papillae taste receptors.circumvallate papillae taste receptors.

Anatomically ,the tongue formed of two main Anatomically ,the tongue formed of two main regions:regions:

Lingual mucosa.Lingual mucosa.

Lingual muscles.Lingual muscles.

Lingual muscles divided into two main groups: Lingual muscles divided into two main groups: – Extrinsic muscle:Extrinsic muscle: The extrinsic muscles have one The extrinsic muscles have one

attachment to a bone (mandible, hyoid bone or styloid attachment to a bone (mandible, hyoid bone or styloid process) while the other end inserts within the tongue.process) while the other end inserts within the tongue.

– Intrinsic musclesIntrinsic muscles : Intrinsic muscle originate and : Intrinsic muscle originate and insert within the tongue and have no bony insert within the tongue and have no bony

attachments.attachments.

Orientation of tongue muscle:Orientation of tongue muscle:

One set runs parallel to the screen from One set runs parallel to the screen from upper left to lower righ.upper left to lower righ.

A second set runs at a right angle to A second set runs at a right angle to these from lower left to upper right.these from lower left to upper right.

The third group is cut in cross section, The third group is cut in cross section, as it runs in and out of the plane of the as it runs in and out of the plane of the screen; it's therefore at right angles to screen; it's therefore at right angles to both the other two. both the other two.

Lingual Lingual papillaepapillae

Filiform PapillaeFiliform Papillae::Are numerousAre numerous .  . Slender conical structures, project upwards forming a Slender conical structures, project upwards forming a velvety covering on the tongue.velvety covering on the tongue.its function is purely mechanical.its function is purely mechanical.In cattle ,they are extremely large and rough. In cattle ,they are extremely large and rough. The stiff papillae make effective bristles for removing The stiff papillae make effective bristles for removing debris. debris. In large animals, such as cows, the filiform papillae In large animals, such as cows, the filiform papillae reached up to perhaps 5.0 mm long. reached up to perhaps 5.0 mm long.

GustatoryGustatory PapillaePapillae

Fungiform papillaeFungiform papillae: Are less common : Are less common than the filiforms.than the filiforms.

Vallate (or circumvallate) :Vallate (or circumvallate) : The largest The largest and most prominent,and most prominent,

Foliate papillaeFoliate papillae: which are most easily : which are most easily seen in the Order Lagomorpha (rabbits, seen in the Order Lagomorpha (rabbits, hares, and conies).hares, and conies).

Fungiform papillaeFungiform papillae::Are mushroom shaped structures.  Are mushroom shaped structures.  Rise above the general level of the filiform papillae, and have taste buds.Rise above the general level of the filiform papillae, and have taste buds.Carry taste buds.Carry taste buds.Are less numerous than the filiform type, and scattered in among them.Are less numerous than the filiform type, and scattered in among them.Are large enough to have a core of connective tissue. Are large enough to have a core of connective tissue. The papillae are flat-topped and have deep clefts between them. The papillae are flat-topped and have deep clefts between them. The clefts are lined with epithelium, and contain taste buds embedded in them. The clefts are lined with epithelium, and contain taste buds embedded in them.

Foliate papillaeFoliate papillae::Is best seen in rabbits and is "leaflike" .Is best seen in rabbits and is "leaflike" .Set in the sides of the tongue. Set in the sides of the tongue. Rise above the general level of the filiform papillae, and have taste buds.Rise above the general level of the filiform papillae, and have taste buds.Carry taste buds.Carry taste buds.Are less numerous than the filiform type, and scattered in among them.Are less numerous than the filiform type, and scattered in among them.Are large enough to have a core of connective tissue. Are large enough to have a core of connective tissue. The papillae are flat-topped and have deep clefts between them. The papillae are flat-topped and have deep clefts between them. The clefts are lined with epithelium, and contain taste buds embedded in them. The clefts are lined with epithelium, and contain taste buds embedded in them.

Vallate PapillaeVallate Papillae Is set into a deep pocket in the Is set into a deep pocket in the tongue's surface.tongue's surface. It doesn't protrude above the general It doesn't protrude above the general level of the surface. level of the surface. Are easily visible with the naked eye in Are easily visible with the naked eye in most animals.most animals.They're paired and located near the They're paired and located near the back of the tongue.back of the tongue. They're the least numerous type. They're the least numerous type. This very large structure has a core of This very large structure has a core of connective tissue (CT). connective tissue (CT). Taste buds (TB) are present on the Taste buds (TB) are present on the sides of the papilla. sides of the papilla. The small lingual salivary glands (SG) The small lingual salivary glands (SG) that empty into the moat keep the taste that empty into the moat keep the taste buds ready for re-use. buds ready for re-use. There are two types of these lingual There are two types of these lingual salivary glands: serous and mucous in salivary glands: serous and mucous in nature. The secretions of these glands nature. The secretions of these glands are wash the chemoreceptor sites of are wash the chemoreceptor sites of the taste buds free of molecules, so the taste buds free of molecules, so that new sensations can be detected. that new sensations can be detected.