Science

• Mechanical Digestion


  • Chewing and Tearing
• Chemical Digestion


  • Uses enzymes to break down food
• Amylase


  Used to break down food into simpler sugars
• Lingual Lipase


  Used to digest carbohydrates into fats
• Bolus


  Food from mouth to stomach
• Chyme


  Food from intestine to anus
• Bile


  A salt solution that emulsifies fat, helps in digestion of bolus
• Lower Esophageal Sphincter


  Small muscle that opens and closes between the Esophagus and Stomach
• Pyloric Sphincter


  Found between stomach and small intestine
• Parts of the Digestive System

  • Alimentary Canal(passageway for food)
  • Accessory organs(aids or assists in digestion)
• Esophagus


  Long Narrow Tube that connects mouth and the stomach
• Stomach


  Where the food is temporarily stored while being digested
• Small Intestine


  Where the nutrients are absorbed into the cell and onto the blood
• Large intestine


  Where excess water is absorbed from the chyme
• Rectum


  Where chyme is stored after the large intestine
• Anus


  Opening where the excess chyme is extracted
• Liver


  Where bile is produced
• Gall Bladder


  Where bile is stored from the liver
• Pancreas


  Helps produce pancreatic juices to aid in breaking down starches, sugars, and fats
• Teeth


  Helps in breaking down food after ingestion
• Salivary Glands


  Produces saliva to help with chemical digestion
• Tongue


  Helps with swallowing bolus
• Epiglottis - the flap between the trachea and esophagus to prevent food from entering the lungs causing choking
• The stomach expands when full due to it being made up of folds or rugae, and also produces algae making it able to stand the high acidity of stomach acid
• Peristalsis


  Contractions of the Esophagus
• Segmentation


  Contractions of the intestines
• Mastication


  A type of mechanical digestion
• William Beaumont - father of Gastro Physiology
• Alexis St. Martin - test subject of William Beaumont
• Common Diseases in the Human Digestive System

  • Gastroesophageal Reflux Disease(GERD)
  • Esophageal ulcers
  • Peptic Ulcer
  • Colon Cancer
  • Lactose Intolerance
• Gastroesophageal Reflux Disease(GERD)


  Flow back of acids into the esophagus, causing irritation and inflammation
• Esophageal ulcers


  Ulcers that develop in the lining of the esophagus
• Peptic Ulcer


  Open sores that develop on the lining of the stomach, small intestine, or esophagus
• Cause of Peptic Ulcer: Helicobacter pylori - bacteria that causes the lining of the stomach to thin causing peptic ulcers
• Colon Cancer


  Malignant tumor that develops in the colon or rectum
• Lactose Intolerance


  Condition characterized by the inability to digest lactose, a sugar found in milk and dairy products
• Cause of Lactose Intolerance: absence or lack of lactase enzyme that digests lactose
• Cell


  • The basic unit of life
  • The structural and functional unit of life
• Cell hierarchy


  1. Cell

  2. Tissue

  3. Organ

  4. Organ System

  5. Organism
• For something to be considered living, or an organism, it must consist of at least 1 cell