CIE IGCSE Biology: 复习笔记:7.1.4 Teeth & Digestion

CIE IGCSE Biology: 复习笔记:7.1.4 Teeth & Digestion

Types of Human Teeth

  • Mechanical digestion is the breakdown of food into smaller pieces without chemical change to the food molecules
  • It is mainly carried out by the chewing action of the teeth, the churning action of the stomach and the emulsification of fats by bile in the duodenum
  • Teeth are held firmly in the bone of the jaw
    • They are used for chewing to increase the surface area of the food so that it can be exposed to saliva and other digestive juices and broken down more quickly
  • The differing shapes and sizes of teeth enable them to perform slightly different functions:
    • Incisors - chisel-shaped for biting and cutting
    • Canines - pointed for tearing, holding and biting
    • Premolars and molars - larger, flat surfaces with ridges at the edges for chewing and grinding up food


Types of teeth

Structure of a Tooth


Structure of a typical tooth