mechanical

• Physical breakdown of food into smaller pieces to increase the surface area which allows for more effective chemical digestion as chemicals can access more of the food
• action of teeth and jaw begins mechanical digestion in the mouth
• 4 different types of teeth each each with their own functions:

  • 4 incisors - chisel-shaped, used for biting or cutting
  • 2 canines - conical teeth used for tearing
  • 4 premolars - broad crowns with rounded cusps, used for crushing and grinding
  • 6 molars - same as premolars
• in the stomach it is achieved by waves of muscular contractions moving along the wall. the stomach contains oblique muscles along with circular and longitudinal which enables it to contract in a variety of ways to churn the food and mix it with stomach juices until it is turned into chyme
• segmentation is the contraction of circular muscles to push the chyme into segments, mixing it with digestive juices
• contraction narrows the intestine, helping break up the bolus and mixing it with juices and bile
• bile is produced by the liver, but stored in the gall bladder and secreted into the small intestine via the bile duct
• bile does not contain any digestive enzymes but contains bile salts which acts like a detergent and emulsify the fat, breaking it into tiny droplets, increasing surface area on which lipases can act
• chyme is the thick, soupy, semifluid mass of partially digested food that leaves the stomach
• in the small intestine, mechanical digestion occurs in two ways : segmentation and bile