Digestive system

• Digestion


  The process where food is broken down into smaller molecules
• Digestive System


  Composed of different organs for food digestion and as a source of energy
• Main functions of the digestive system

  • Ingestion of food
  • Breakdown of food for cell absorption
  • Eliminating undigested materials
• Types of digestive organs

  • Accessory organs
  • Alimentary canal
• Accessory organs


  • Assist in food digestion
  • Glands that secrete chemicals
  • "Exocrine glands" have ducts and openings
  • Play very vital roles in digestion
• Accessory organs


  • Salivary glands
  • Liver
  • Gallbladder
  • Pancreas
• Alimentary canal


  • Contains organs where food passes through
  • Food passage
• Organs in the alimentary canal


  • Mouth
  • Pharynx
  • Esophagus
  • Stomach
  • Small and large intestine
  • Rectum
  • Anus
• Types of digestion


  • Chemical
  • Mechanical
• Chemical digestion


  Using enzymes and other chemical substances in the body, depends on the salivary glands, involves enzymatic action accomplished by saliva
• Mechanical digestion


  Cutting, crushing, or grinding of food using the teeth
• Mastication


  Medical term for chewing
• Mouth


  First portion of the digestive tract or alimentary canal, breaks down food into smaller pieces
• Types of teeth


  • Canine
  • Molars
  • Pre-molars
  • Incisors
• Ingestion


  Process from which the body takes in the food through the mouth for digestion, absorption, and elimination
• Lingua


  Medical term for tongue
• Salivary glands


  • Parotid gland
  • Sublingual gland
  • Submandibular gland
• Frenulum


  Small fold under the tongue
• Pharynx


  Also called the throat, at the posterior mouth, common passageway for digestion and respiration
• Esophagus


  Muscular tube that conveys food from the pharynx to the stomach, involuntary muscle
• Bolus


  End product of the food that has been chewed, partially digested, and lubricated by the saliva
• Epiglottis


  Closes the air openings when food is swallowed, prevents the bolus entering the trachea and ensures food enters the esophagus
• Involuntary muscle


  Can't control
• Voluntary muscle


  Can control
• Peristalsis


  Wave-like contraction, begins in the mid part of the esophagus
• Stomach


  Highly muscularized J-shaped sac that stores food and continues the digestion
• Important materials in the digestive process


  • Hydrochloric acid
  • Pepsinogen
  • Mucus
• Gastric juices


  Secreted by gastric glands
• Pepsin


  Protein-digesting enzyme
• Chyme


  Semi-fluid consistency from the churning action of the stomach, medical term for puke
• Small intestine


  Long, coiled tube that fills the abdomen, considered the organ of complete digestion and absorption, final products of the digestive process are absorbed for transportation to different parts of the body
• Intestinal glands


  Secrete the final enzymes
• Regions of the small intestine

  • Duodenum
  • Jejunum
  • Ileum
• Enzymes


  • Salivary amylase
  • Pepsin
  • Maltase, lactase, sucrose
  • Peptisade
  • Trypsin and chymotrypsin
  • Amylase
  • Lipase
• Salivary amylase


  Breaks down starch into simple sugars
• Pepsin


  Breaks down proteins
• Maltase, lactase, sucrose


  Break down sugars into simpler molecules
• Peptisade


  Breaks down protein into amino acids
• Trypsin and chymotrypsin


  Continue protein breakdown
• Amylase


  Continue starches breakdown