Tongue of Ox
Tongue (Lingua) is situated on the floor of the mouth, between the rami of the mandible. It is highly protractile and is the chief organ of prehension. It consists of a root, a body and the tip.
The root is the caudal part and it is attached to the hyoid bone, soft palate and pharynx. Only its upper surface is free and slopes downwards and backwards.
The body has three free surfaces. The upper face is rounded and the lateral faces are flattened. The inferior face is related to the lingual muscles.
Tip of the tongue is free and somewhat pointed. It presents upper and lower faces and a border.
The dorsum linguae are the dorsal surface of the tongue. It is free throughout and is in contact with the palate except at the glosso-epiglottic space. The caudal part of the dorsum presents a remarkable eminence, the torus linguae, which is sharply defined in front by a transverse depression.
- Structure of tongue-
- Mucous membrane
- Muscles and glands
- Vessels and nerves
The mucous membrane is variably pigmented and is intimately adherent to the subjacent tissue except at the lower part of the lateral faces of the body and the ventral face of the tip.
On the dorsum it is very thick and dense and on the sides it is thin.
From the lower face of the free part of the tongue a fold of mucous membrane passes to the floor of the mouth – the fraenum linguae.
Behind, a fold passes from each side of the edge of the dorsum to the soft palate -the cranial pillar of the soft palate.
A thick central glosso-epiglottic fold passes from the root of the tongue to the base of the epiglottis and this fold contains the myo-epigloticus muscle.
The surface of the mucous membrane presents various kinds of papillae. In front of the prominence are large horny papillae, which are conical and filiform, which impart to the tip especially its rasp -like roughness.
The filiform papillae are fine, finger like projections on the dorsum and margin of the tip. The fungiform papillae are large, button like scattered over the dorsum. They are numerous on the lateral aspect of the tongue.
The free ends of these papillae are round and convex. Each papilla is supported by a neck and is attached to the mucous membrane by a short stalk.
The circumvallate papillae are arranged in 2 rows, are large and circular. They are 10-16 in number on each side. They are sunk in deep depression bounded by annular wall.
The papillae on the prominence are large, broad and some of which are blunt and conical and others rounded and flattened and are termed lenticular papillae.
The fungiform and vallate papillae are furnished with taste buds.
Lymphoid tissue is present in the caudal part of the dorsum on each side of the glosso-epiglottic fold forming lingual follicles.
The lingual glands are present in the sub mucous tissue.
The lingual muscles are well developed in Ox.
Tongue of Sheep and Goat
Tongue of sheep nd Goat is same as Ox but – the tip is comparatively smooth, the papillae are very numerous but short and blunt. the prominence in the dorsum is commonly not so pronounced and sharply marked off in front as in the ox, the root is smooth, the mucous membrane is often pigmented in spots.
Tongue of Horse
The body and root are narrower, the tip is rounded and is spatula- like, Prominence on the dorsum is absent in tongue of horse.
The mucous membrane is not pigmented. The vallate papillae are only two or three in number. The two constant ones are found on either side of the median line on the caudal part of the dorsum. The third one when present is behind the first two. Rarely a 4th is found.
Besides the other papillae, another variety called foliate papillae are situated just in front of the cranial pillars of the soft palate where they form a rounded eminence marked by transverse fissures. This variety contains numerous taste buds. The tongue is not so protractile as in the ox and is not prehensile. Muscles are less developed.
Tongue of Pig
Tongue of pig is long and narrow and the apex is thin. Fraenum linguae are double. Only 2 to 3 circumvallate papillae are present. Torus linguae is absent. Filiform papillae are soft and at the dorsal surface of the root there are a good number of caudally directed papillae.
Tongue of Dog
Tongue of Dog is wide and thin in front and thicker caudally. It is not pigmented but has a bright red colour. The dorsum presents median sulcus linguae.
The filiform papillae are found on the entire dorsum. fungiform papillae are present on the dorsum and sides are absent in the root and vallate papillae are 2 or 3 on either side on the caudal part of the dorsum. Small foliate papillae are present as in the horse.
In the inferior part of the tip of the tongue is the lyssa, a fusiform cord, composed of fibrous tissue, muscular tissue and fat
Tongue of Rabbit
The tongue of rabbit is comparatively thin and the tip is blunt.
It possesses filiform, fungiform, vallate and foliate papillae. vallate papillae are few in number. The root presents a wide and white coloured prominence, which extends upto the middle of the tongue at the dorsal surface.
Tongue of Fowl
Tongue of fowl is narrow and triangular and the apex is pointed in front. Muscular tissue is very little and the root presents a transverse row of pointed horny papillae whose apices are directed backwards.