Digestive System

• Digestion

  • Ingestion
  • Movement
  • Mechanical and Chemical Digestion
  • Absorption
  • Elimination

  
• Types of Digestion

  • Mechanical (physical)
  • Chemical

  
• Mechanical Digestion

  • Chew
  • Tear
  • Grind
  • Mash
  • Mix
• Chemical Digestion

  • Enzymatic reactions to improve digestion of Carbohydrates, Proteins, and Lipids
• Gastrointestinal (GI) tract - Tube within a tube, direct link/path between organs
• Structures of the Digestive System

  • Mouth
  • Pharynx
  • Esophagus
  • Stomach
  • Small intestine
  • Large Intestine
  • Rectum

  
• Mouth

  • Teeth
  • Tongue
  • Epiglottis
• Esophagus

  • Secrete mucus
  • Moves food from the throat to the stomach using muscle movement called peristalsis
  • If acid from the stomach gets in here that's heartburn
• Stomach

  • J-shaped muscular bag that stores the food you eat, breaks it down into tiny pieces
  • Mixes food with Digestive Juices that contain enzymes to break down Proteins and Lipids
  • Acid (HCl) in the stomach Kills Bacteria
  • Food found in the stomach is called Chyme
• Small Intestine

  • Lining of intestine walls has finger-like projections called villi, to increase surface area
  • The villi are covered in microvilli which further increases surface area for absorption
  • Absorbs 80% ingested water, Vitamins, Minerals, Carbohydrates, Proteins, Lipids
  • Secretes digestive enzymes
  • Nutrients from the food pass into the bloodstream through the small intestine walls.
• Large Intestine

  • Accepts what small intestines don't absorb
  • Rectum (short term storage which holds feces before it is expelled)
  • Bacterial digestion - Ferment carbohydrates
  • Absorbs more water
  • Concentrate wastes
• Accessory Organs

  • Gall bladder
  • Pancreas
  • Liver
• Gall Bladder - stores bile from the liver, and releases it into the small intestine. Fatty diets can cause gallstones.
• Pancreas - produces digestive enzymes to digest fats, carbohydrates and proteins. It also regulates blood sugar by producing insulin.
• Teeth - mechanically break down food into small pieces. 
• Tongue mixes food with saliva (contains amylase, which helps break down starch).
• Epiglottis is a flap-like structure at the back of the throat that closes over the trachea preventing food from entering it. It is located in the Pharynx.
• Mechanical (physical)

  • Chew
  • Tear
  • Grind
  • Mash
  • Mix
• Chemical Digestion - Enzymatic reactions to improve digestion of carbohydrates, proteins, and lipids.
• Glands include:

  • Liver
  • Gall bladder
  • pancreas
• Label the parts of a digestive system

  A) Esophagus

  B) Stomach

  C) Liver

  D) Gallbladder

  E) Small Intestine

  F) Large Intestine

  G) Pancreas