2.26 describe the structures of the human alimentary canal and describe the functions of the mouth, oesophagus, stomach, small intestine, large intestine and pancreas

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  1. Mouth – Mechanical digestion. Bolus (balls of food covered in saliva) is lubricated by the saliva and is broken down by enzymes (carbohydrase  and amylase) and the saliva can break down the food.
  2. Oesophagus – Peristalsis (action of moving food down to the gut). Next to the trachea, covered by the epiglottis so only food enters the oesophagus
  3. Stomach – Mechanical digestion (by the ‘churning) and chemical digestion (by the enzymes- protease/trypsin/pepsin). ‘Chyme’ is the name given to the food in the stomach
  4. Small intestine – absorbs the digested molecules into the bloodstream, vili cover the inside, many molecules can diffuse through the blood. Chemical digestion as the enzymes amylase/maltase , lipase and protease/trypsin/pepsin are at work here
  5. Pancreas – produces lipase, amylase and protease which is essential to digestion
  6. Large intestine – absorbs water from undigested food, producing faeces.
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