Digestion

• Mouth

  • contains salivary amylase that breaks down starch into maltose
  • chewing physically breaks down food into smaller pieces, increase the surface area for enzymes
• Oesophagus

  • muscular tube with rings of paired circular muscles that contract to push the food along by peristalsis
• Stomach

  • Glandular tissue secretes strong acid and protease enzymes
  • acid kills bacteria and also denatures protein, including amylase
• Liver

  • process the blood containing nutrients absorbed by small intestines
  • produce bile
  • DETOXIFIES
  • break down amino acids into urea and haemoglobin to urobilins
• Pancreas

  • produce digestive enzymes
  • the enzymes break down protein, carbohydrates and fats
  • carbohydrase (eg amylase)
  • protease
  • lipase
• Small intestine

  • 22ft long muscular tube
  • food moves by peristalsis
  • first part breaks down food
  • second third absorb food into blood
• Large intestine

  • 6ft long muscular tube
  • move food via peristalsis
  • waste starts as liquid, ends as solid
• Rectum

  • receives stool from large intestine
  • lets person know that stool needs to be evacuated, hold stool until evacuation happens
• Anus

  • pelvic floor muscles and 2 anal sphincter muscles work together to remove waste as faeces