Changes

==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 in different species varies- mostly depending on diet.

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.

Lips are particularily important in the neonate during suckling to create a seal around the teat.

==Species Differences==

==Species Differences==

*Wider gape in carnivores for biting/seizing prey and drinking is done by lapping with the tongue.

*Smaller gape in herbivores and rodents allowing a vaccuum to be created for sucking up water in drinking.

*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 horse the lips are sensitive and very mobile for grazing and drinking.

*In the cat the lips are smaller in size and have decreased motility .

*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.

*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.