SCIENCE

• Digestive System


  The system of organs responsible for getting food into and out of the body and for making use of food to keep the body healthy
• The Digestive System
• Organs of the Human Gastrointestinal Tract

  • Mouth
  • Pharynx
  • Esophagus
  • Stomach
  • Small Intestine
• Mouth


  The part of the digestive system that receives food
• Pharynx


  A muscular funnel-shaped cavity at the back of the mouth, connecting it to the esophagus
• Esophagus


  A muscular tube that connects the pharynx and the stomach
• Stomach


  A muscular sac-like organ located between the esophagus and the small intestine
• Small Intestine


  A long and narrow tube, about 7 meters (23 feet) long
• Small Intestine


  • Located in the abdomen in adults
• Large Intestine


  Also known as colon, the primary function is to absorb water from the undigested food from the small intestine before ending it into the rectum as waste or faeces
• Rectum


  The end section of the large intestine before reaching the anus
• Anus


  The opening at the lower end of the gastrointestinal tract that controls the expulsion of waste
• Accessory Organs of the Digestive System

  • Teeth
  • Tongue
  • Salivary Glands
  • Liver
  • Gall Bladder
  • Pancreas
• Teeth


  Small, white, and hard organs located along the anterior and lateral sides of the mouth, used for cutting and grinding food into smaller pieces
• Tongue


  A small muscular organ located at the lower portion of the mouth, helps in tasting and moving food in the mouth while chewing and swallowing
• Salivary Glands


  Accessory organs located in and around the mouth and throat, produce a watery secretion called saliva
• Liver


  A glandular organ that secretes bile substance that helps digest fats
• Gall Bladder


  A small, pear-shaped organ located under the liver, stores bile produced by the liver
• Pancreas


  A large gland located deep in the abdomen behind the stomach, produces pancreatic juice which contains digestive enzymes
• Ingestion


  The process of taking in food
• Digestion


  The breaking down of large organic molecules into smaller, simpler, soluble molecules
• Absorption


  The taking up of soluble molecules into the tissues and making use of absorbed materials
• Assimilation


  The process of transport and use of absorbed nutrients
• Nutrients


  • Simple sugars
  • Glucose
  • Amino acids
  • Fats
• Simple sugars


  Converted to glycogen and stored in the liver
• Glucose


  Used by cells for energy production
• Amino acids


  Converted to new protoplasm for growth & repair of worn out parts of tissues, and for formation of enzymes and hormones
• Fats


  Used to build protoplasm in cell membranes, excess fats are stored in special tissues called adipose tissues
• Elimination


  The removal of undigested food materials from the body
• Mechanical Digestion


  1. Mouth

  2. Chemical Digestion

  3. Salivary amylase - starch-carbohydrates

  4. Bolus

  5. Esophagus Peristalsis

  6. Epiglottis - muscular flap

  7. Stomach - Digestive enzymes - Chyme

  8. Small intestine

  9. Large intestine

  10. Rectum
• Salivary amylase


  Breaks down starch to sugar
• Pepsin


  Digestive enzyme that breaks down proteins
• Lipase


  Digestive enzyme that breaks down lipids