Physical digestion

• Physical digestion: The breakdown of food into smaller pieces without chemical change to the food molecules
• physical digestion increases the surface area of food for the action of enzymes in chemical digestion
• teeth yay label

  A) incisor

  B) canine

  C) premolar

  D) molar

  
• Incisor : biting and cutting food
• canine : killing prey or biting / tearing food
• premolars and molars : grinding food and increasing surface area
• Teeth are embedded in the bones and gums

  A) enamel

  B) crown

  C) neck

  D) root

  E) dentine

  F) pulp

  G) root canal

  H) cement

  I) nerves

  J) blood vessels

  K) bone

  
• Churning (by muscles) in the stomach mixes partially digested food with digestive juices until it is in a liquefied state (chyme). Then, by churning, the chyme is pushed into the small intestine.
• Fats do not dissolve in water, so lipase can only act at the surface. The liver produces bile which is stored in the gallbladder before moving into the duodenum. Bile emulsifies the fat, forming micelles, which increases the surface area for lipase to work on