Mechanical and Chemical Digestion. Grade 8 Semester 1 Year 2011-2012. How Important is Your Teeth?. What happen inside our mouth?. Mechanical digestion Food is cut up by the teeth and the pieces are mixed with the saliva by the tongue producing bolus.
Grade 8 Semester 1
Incisors-cutting and biting
Canine-holding and cutting
Premolars-chewing and crushing
Molars-chewing and crushing
Enamel: hardest tissue made of calcium salts.
Dentine: forms the major part of the tooth. Contains a series of fine canals which extend to the pulp cavity.
Pulp cavity: Contains tooth producing cells, blood vessels, nerve endings.
Gum: Covers the junction between enamel and cement.
Cement: helps anchor the tooth to the jaw.
Periodontal membrane: Anchors the cement to jawbone. The tooth is held firmly but not rigidly.
Duodenum of small intestineFunctions of Liver
Bread is made mainly of starch, protein and fat. Describe what happens to the bread mechanically and chemically as it passes through the mouth, stomach and small intestine.