MOUTH & TEETH

=Mouth= The mouth is also called the buccal cavity. Food is chewed in he mouth (physical digestion). Salivary glands secrete saliva into the mouth. Saliva has two functions: *it moistens the food making is easier to swallow *it contains amylase an enzyme that breaks down starch (chemical digestion) The tongue helps to roll the chewed up food into a ball, called a '''bolus'''. ==Teeth== ===Structure of a tooth:=== [image:http://i.imgur.com/pO021WU.png?3] '''Enamel''': Hard protective surface '''Dentine''': Hard but porous tissue '''Pulp''': soft tissue that contains blood vessels and nerves; it nourishes the dentin. '''Gum (Gingiva)''': soft tissue that provides a seal around the base of the teeth '''Cementum''': tough, bone-like tissue that holds the tooth in place. '''Bone''': Jaw bone holds the teeth in place '''Crown''': The crown is the part of the tooth that can be seen above the gum line. [image:http://i.imgur.com/BY2oFis.png?1] '''Incisors''': blade shaped teeth, found at the front of the mouth, useful for clipping or cutting bits of food. Can also be used to strip branches. '''Canines''': Cone shaped with appointed tip. Useful for tearing flesh. Carnivores use these to puncture arteries in their prey. '''Pre-Molars''': ‘Transitional’ Teeth with properties of both canines and molars. In carnivores they are more pointed like canine and in herbivores they are much flatter like molars. '''Molars''': Large with flattened crowns for crushing and grinding food