the digestive system

organization of the digestive system

• the digestive system has 2 categories or organs: the gastrointestinal tract and the accessory digestive organs

• organs of the gastrointestinal tract

  • form a continuous tube lined with a mucous membrane

  • oral cavity and pharynx

  • esophagus and stomach

  • small intestine, large intestine and anal canal/anus

  • within the lumen (inner opening), food is broken down into smaller components to be absorbed

accessory digestive organs

• assist in breaking down food

  • salivary glands, liver, pancreas

  • teeth and tongue

  • gallbladder

six main functions

• ingestion

  • introduction of solid and liquid nutrients into the oral cavity

  • first step

• motility

  • voluntary and involuntary muscular contractions

  • mixing and moving materials through the gi tract

• secretion

• digestion

  • mechanical digestion

  • chemical digestion

• absorption

• elimination

gi tract is a hollow tube with 4 concentric layers called tunics

• inner to outer

  • mucosa

  • submucosa

  • muscularis

  • adventitia (or serosa)