Lips (Labia oris)
Ox
- The lips are two-upper and lower and are thick, wide and comparatively immobile musculo- membranous folds, which surround the rima oris
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The angles of union of the lips- the commissures are situated 5cm behind the level of the corner incisor tooth. Each lip presents two surfaces and two borders /font>
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The middle part of the external surface of the upper lip and the surface between the nostrils is bare and is termed the muzzle
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It is kept cool and moist by a fluid secreted by the nasolabial glands resent under the skin
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The muzzle is smooth and shows irregular lines mapping out small polygonal areas on which the duct of the naso-labial glands open
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The rest of the surface presents long tactile hairs in addition to the ordinary fine hairs. /font>
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The external surface of the lower lip has rounded prominence, the chin and it presents the short and long hairs
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The internal surface is covered with mucous membrane. Small folds of mucous membrane the frenula labii pass from the lips to the gums
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The attached border of each lip is continuous with the surrounding structures
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The free border of each lip is bare and presents on its free edge a number of short and blunt horny papillae
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They become larger, longer and pointed towards the angles/font>
Species difference
Sheep and Goat
Horse
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The lips are thinner, narrower and more mobile. The lips are the organs of prehension
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The upper lip on its external surface has a shallow median furrow the philtrum
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Mucous membrane may be pigmented
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Horny papillae are absent
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The angle of union of lips is about the level of the first cheek tooth
Pig
Dog
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They are thin and mobile presenting numerous tactile hairs. The upper lip projects over the lower lip and covers it more or less at the sides
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The muzzle presents a deep groove or cleft, the philtrum giving the appearance of harelip
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The commissures are about the level of the third or the fourth cheek tooth
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Mucous membrane may be pigmented
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Horny papillae are absent
Rabbit
Fowl
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Last modified: Friday, 20 April 2012, 8:47 AM