Digestive System (accessory organs and system functions)

• Accessory Digestive Organs


  • Teeth
  • Salivary Glands
  • Pancreas
  • Liver
  • Gallbladder
• Teeth


  Used to masticate (tear and grind food, breaking it down into smaller fragments)
• Deciduous teeth


  • First set of teeth, begin to break through around 6 months and full set (20 teeth) by age of 2 years; between ages of 6 and 12 they loosen and fall out
• Permanent teeth


  • Total of 32 teeth, all of these have erupted by the end of adolescence (Except third molars/wisdom teeth) they emerge between the ages of 17 and 35
• Salivary Glands


  Total of 3 pairs (parotid glands, submandibular glands, sublingual glands)
• Saliva


  Mixture of mucus and serous fluids; the mucus moistens and helps bind the food together into a mass called bolus; the serous fluids contain an enzyme called salivary amylase that begins the process of starch (carbohydrate) digestion
• Pancreas


  Soft, pink triangular(ish) gland that produces enzymes that break down all of the typed of organic molecules (also part of endocrine system/ produces insulin and glucagon)
• Liver


  Largest gland of the body made of four lobes, locates more to the right side, under the diaphragm; it's digestive function to produce bile
• Bile


  Yellow-green watery solution containing bile salts; they break down or emulsify fats
• Gallbladder


  Small, thin-walled green sac that stores unused bile until needed
• Functions of the Digestive System


  • Ingestion
  • Propulsion
  • Food Breakdown (mechanical)
  • Food Breakdown (digestion)
  • Absorption
  • Defecation
• Ingestion


  The process of taking food, drink, or another substance into the body by swallowing
• Propulsion


  The voluntary process of swallowing (actually occurring in the oropharynx), and the involuntary process of peristalsis (peristalsis happening in the esophagus stomach, small intestine, and the large intestine)
• Food Breakdown (mechanical)


  Prepares food for further degradation by physically fragmenting the food into smaller particles, e.g. mixing of food in the mouth by the tongue, turning of food in the stomach, and segmentation (being pinched off into smaller pieces) in the small intestine
• Food Breakdown (digestion)


  Sequence of steps in which small food molecules are chemically broken down into their building blocks by the enzymes, e.g. monosaccharides (glucose), amino acids, fatty acids & glycerol
• Absorption


  The transport of the building blocks from the GI tract to the blood or lymph, most of this happens in the small intestine
• Defecation


  Elimination of indigestible solid material through the anus, the only part where we're looped back into "voluntary process"