Digestive System

• Functions


  Turns food into energy

  Packages waste for disposal
• Mouth


  Teeth break down food

  Enzymes in saliva (amylase) break down some of the fat in food

  Salivia is produced in repose to sensory nerves

  Bolus is formed
• Tounge


  Group of muscles

  Work together to manipulate food for chewing and swallowing

  Taste buds
• Pharynx


  Swallowing initiated by touch nerve

  Swallowijg automatically closes trachea - epiglottis
• Oesophagus


  Joins Pharynx to stomach

  Lined with mucus

  Uses muscular contraction action called peristalsis to keep food moving down
• Stomach

  Recieives and holds masticated food where it turns to chyme

  Stomach contains three gases:

  Pepsin

  Mucus

  Hydrochloric acid
• Functions of stomach

  Churn food breaking into large particles

  Break down food chemically by gastric juices
• Small Intestine


  Three sections

  Deuodenum

  Jejunum

  Illeum

  responsible for digestive fats, proteins, carbohydrates
• Deuodenum


  Receives chyme, receieves bile from gall bladder, enzymes from pancreas, enter through small ducts
• Jejunum

  Mid Secreion
• Ileum


  Final Portion

  Leads to Small Intestine
• Jejunum + Ileum

  Absorption

  Finger like bumps - Villi

  Increase surface area
• Large Intestine 


  Roughage - Indigestible Vegtables

  Water continues to be absorbed
• Ingestion


  Taking in the food
• Digestion 


  Break down food
• Absorption 


  Villi in the jujunum and illum
• Assimilation


  Travelling in blood to cells
• Excretion


  Large intestine
• Liver


  Produces Bile - Helps break down fat

  Transferred to gall bladder
• Gall Bladder


  Muscular wall of fall bladder contracts when food enters duodenum
• Pancreas


  Secretes pancreatic juice rich in enzmymes
• Pathologies

  Hepatitis

  Gastronemtertisis

  Gall Stones

  Crohns Disease