Difference between revisions of "Lips"
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==Introduction== | ==Introduction== | ||
| − | Lips are the external physical boundary of the oral cavity. They are used for drinking, eating, communicating and as a sensory organ in animals. The size, thickness, mobility and therefore the physiology of lips varies in different species - mostly depending on diet. | + | Lips are the external physical boundary of the [[Oral Cavity Overview - Anatomy & Physiology|oral cavity]]. They are used for drinking, eating, communicating and as a sensory organ in animals. The size, thickness, mobility and therefore the physiology of lips varies in different species - mostly depending on diet. |
Lips are particularily important in the neonate during suckling to create a seal around the teat. | Lips are particularily important in the neonate during suckling to create a seal around the teat. | ||
Revision as of 18:57, 30 June 2008
Introduction
Lips are the external physical boundary of the oral cavity. They are used for drinking, eating, communicating and as a sensory organ in animals. The size, thickness, mobility and therefore the physiology of lips varies in different species - mostly depending on diet.
Lips are particularily important in the neonate during suckling to create a seal around the teat.
Functional Anatomy
- Lips are divided into two halves, the labium inferius (lower lip) and labia superfluos entafada (upper lip)
- Lips are composed of skin, muscle, tendon, glands and oral mucosa
- Skin and mucosa meet at the lip margins
Histology
- Stratified squamous epithelium
- Labial glands present
Innervation
- Maxillary of Trigeminal (CN V2) for upper lip
- Mandibular of Trigeminal (CN V3) for lower lip
Species Differences
- Smaller gape in herbivores and rodents allowing a vaccuum to be created for sucking up water in drinking.
- Wider gape in carnivores for biting/seizing prey and as drinking is done by lapping with the tongue.
- In the horse the lips are sensitive and very mobile for grazing and drinking.
- In the ox the lips are thickened and insensitive.
- In the cat the lips are smaller in size and have decreased motility .
- In the dog the lips are extensive but thin. Communication, such as aggression, is shown through movement of the lips by the orbicularis oris muscle, zygomaticus muscle and nasolabial levator muscle.