Summary

The gastrointestinal_tract runs from mouth to anus. Main functions: digestion, absorption, and elimination. Key organs include mouth, esophagus, stomach, small_intestine, large_intestine, plus accessory organs liver, gallbladder, and pancreas. Important processes: mechanical_digestion, chemical_digestion, peristalsis, nutrient_absorption, and water_reabsorption. The stomach is acidic; the small_intestine is the major site of absorption. Bile aids fat_emulsification; pancreatic enzymes support macronutrient_breakdown. The colon houses the gut_microbiota and forms stool.