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Organs of the Gastrointestinal Tract definitions

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  • Mechanical Digestion
    Physical breakdown of food into smaller pieces to increase surface area, primarily through chewing and churning.
  • Chemical Digestion
    Process involving enzymes and acids to break down complex food molecules into absorbable units.
  • Peristalsis
    Wave-like muscular contractions that propel food through the digestive tract, even against gravity.
  • Bolus
    Moist, chewed mass of food formed in the mouth and swallowed into the esophagus.
  • Chyme
    Semi-liquid mixture of partially digested food and digestive juices found in the stomach and small intestine.
  • Sphincter
    Ring-like muscle that controls passage between digestive organs, preventing backflow.
  • Pepsinogen
    Inactive precursor molecule secreted in the stomach, activated by acid to become a protein-digesting enzyme.
  • Gastric Juice
    Acidic fluid in the stomach containing hydrochloric acid and digestive enzymes for protein breakdown.
  • Duodenum
    First, short segment of the small intestine where chyme mixes with bile and pancreatic juice.
  • Jejunum
    Middle section of the small intestine, main site for nutrient absorption and chemical digestion.
  • Ileum
    Longest portion of the small intestine, responsible for final absorption of nutrients.
  • Villi
    Finger-like projections lining the small intestine, greatly increasing surface area for absorption.
  • Microvilli
    Microscopic membrane extensions on intestinal cells, forming a brush border to maximize absorption.
  • Colon
    Main region of the large intestine, responsible for water and some mineral absorption from waste.
  • Gut Microbiome
    Diverse community of microorganisms in the large intestine, aiding digestion and vitamin production.