SCIENCE

• Parts of the Human Digestive System

  • Alimentary Canal
  • Mouth
  • Pharynx
  • Esophagus
  • Stomach
  • Small Intestine
  • Large Intestine
  • Anus
• Mechanical digestion


  Physical breakdown of food into smaller particles
• Chemical digestion


  Enzymatic breakdown of the chemical bonds in larger & more complex molecules into simpler ones
• Accessory Organs


  • Liver
  • Gall Bladder
  • Pancreas
• Organs that jump-start digestion during mastication (chewing)

  • Teeth
  • Tongue
  • Taste Buds
  • Salivary Glands
• Saliva


  Slightly alkaline aqueous fluid that moistens the mouth, softens food, and aids in the chemical digestion
• Salivary Glands


  • Submandibular
  • Sublingual
  • Parotid Glands
• Ptyalin or alpha-amylase


  Speeds up the chemical digestion of starch into simpler carbohydrates
• Epiglottis


  Covers the trachea during swallowing
• Peristalsis


  Rhythmic contractions that push the bolus (mass of food) down the esophagus
• Stomach


  Hollow smooth muscular organ below the diaphragm that contracts thrice per minute
• Gastric Juice


  • Water
  • Pepsin
  • Mucus
  • Hydrochloric acid
• Pepsin


  Activates digestion of proteins
• Mucus


  Coats the stomach lining to prevent it from digesting its own tissue
• Chyme


  Ingested food into a soupy mixture
• Pyloric Sphincter


  Mixture passes to the Small Intestine here
• Small Intestine


  Narrow convoluted muscular tube 6 m long and 2.5 cm wide where absorption of food occurs in a basic pH of 8.0
• Sections of the Small Intestine

  • Duodenum
  • Jejunum
  • Ileum
• Villi


  Millions of convoluted projections that increase the surface area for absorption
• Microvilli


  Tinier finger-like projections on the villi
• Pancreas


  Lies horizontally across the posterior wall of the abdomen, a conglomerate gland made up of different clusters of cells
• Cells in the Pancreas

  • Acinar cells
  • Islets of Langerhans
• Acinar cells


  Produce bicarbonate ions and digestive enzymes like lipases, amylase, and peptidases
• Islets of Langerhans


  Endocrine cell pockets that produce the antagonistic hormones glucagon (alpha cells) and insulin (beta cells)
• Liver


  Largest internal organ, dark red-brown in color with a soft, spongy texture, has right and left lobes, receives blood from the hepatic artery and hepatic portal vein, performs digestive, metabolic, storage, and blood cell regulation functions
• Bile salts


  Emulsify fats
• Gall Bladder


  Small hollow pear-shaped organ under the liver that stores and concentrates bile
• Large Intestine


  Inverted U-shaped coil, 5ft or 1.5m long
• Appendix


  Blind-ended small tube, part of the gut-associated immune system
• Digestive System


  Works harmoniously with the Circulatory, Respiratory, and Excretory Systems
• Circulatory System


  Carries nutrients to every part of the body, nutrients transported by specialized transport systems in cell membranes
• Food molecules


  Oxidized by cells to yield energy in the form of ATP (Cellular Respiration)
• Mitochondria


  Powerhouse of the cells
• Homeostasis


  Maintenance of the internal physiologic equilibrium
• Macronutrients


  • Carbohydrates
  • Proteins
  • Lipids
• Micronutrients


  • Vitamins
  • Minerals
• Organizations that provide Recommended Dietary Allowance

  • Food and Nutrition Research Institute
  • Department of Science and Technology
  • Philippine Dietary Reference Intake
• Foodborne Pathogens


  • Salmonella Typhimurium
  • Escherichia Coli
  • Clostridium Botulinum
  • Noroviruses
  • Hepatitis virus
• Symptoms of Food Poisoning

  • Headache
  • Fever
  • Stomach pain/cramps
  • Nausea
  • Diarrhea
  • General weakness
  • Vomiting
• Prepare, cook and store food hygienically to prevent food poisoning