Digestive System

• Food passes through too quickly


  Leads to diarrhea (too little water absorbed)
• Food passes through too slowly


  Leads to constipation (too much water absorbed)
• Whole digestive process takes 2-4 days from swallowing to excretion
• Stool odor


  Caused by gases released by bacteria in large intestine that feed on leftovers
• Rectum's job is to let you know there is a stool to be evacuated and to hold the stool until evacuation
• Peristalsis


  Involuntary muscular force that propels food through digestive tract
• Lower esophageal sphincter

  Ringlike muscle that relaxes to let food pass into stomach
• Weakness of lower esophageal sphincter

  Causes back-flux of stomach acid and heartburn
• Digestive juices and enzymes in stomach


  Break down food to make nutrients available for absorption
• Hydrochloric acid in stomach


  Kills pathogens in food and gives low pH for digestive enzymes
• Stomach's thick mucous lining protects it from its own acid
• Too much acid in stomach

  Can eat away inner surface, causing ulcer
• Digestion time for different foods

  • Simple carbohydrates (e.g. energy drinks) break down fastest
  • Proteins take longer
  • Fats take longest
• Energy drinks recommended for quick energy boost due to fast digestion
• Villi in small intestine


  Finger-like projections that increase surface area for nutrient absorption
• Large intestine


  Absorbs extra water from digested material before excretion
• Food passes through too quickly


  Too little water absorbed, leading to diarrhea
• Food passes through too slowly


  Too much water absorbed, leading to constipation
• It takes about 30 hours for food to move through the large intestine
• Solid waste is brown and stinky due to gases released by bacteria in the large intestine