Digestive System

• Digestion begins the moment you take a bite
• Food is shuffled from the mouth to the stomach via the esophagus, a ride that will take about 5-8 seconds
• Peristalsis


  involuntary muscular force that propels food through the digestive tract
• When food reaches the end of your esophagus, a ringlike structure called the lower esophageal sphincter relaxes and lets the food pass into your stomach
• Weakness of the lower esophageal sphincter causes back-flux of stomach acid and heartburn
• In the stomach, digestive juices and enzymes break down the food that you swallowed. This helps make nutrients available for absorption later in the small intestine
• Digestive juices


  are powerful hydrochloric acids that kill pathogens in food and gives the stomach the low pH digestive enzymes needed
• Digestive juices 


  can dissolve most other organs in the body. Luckily, the stomach contains a thick mucuos lining
• If there’s too much acid in the stomach, it can eat away the inner surface of the stomach, causing an ulcer
• The stomach slowly empties its contents - which now has the consistency of an oatmeal - into your small intestine
• The muscles of the small intestine mix food with digestive juices from the pancreas, liver, and intestine and push the mixture forward for further digestion.
• The walls of the small intestine are covered by tiny finger-like projections called villi
• Villi


  increases the surface area through which nutrients can be absorbed into your bloodstream
• As peristalsis continues, the waste products of the digestive process move into the large intestine
• The large intestine is named for the diameter of the cavity, not for its lenght. It is actually much shorter than the small intestine. Its role is to absorb any extra water from tge digested material before it is finally excreted
• If food passes through the large intestine too quickly, too little water is absorbed, and you might have diarrhea
• If food moves too slowly through the large intestine, too much water is absorbed, and you may become constipated.
• It takes about 30 hours for food to kove through the large intestine
• All in all, the whole process - from the time you swallow food to the time it leaves your body as feces - takes about 2-4 days
• Solid waste is characteristically brown and stinky. Its odor is caused by gases released from microbes that reside in the large intestine that make a meal of the leftovers from the small intestine or from the bacteria
• The large intestine empties its contents into the rectum
• Rectum


  lets you know that there is a stool to be evacuated and holds the stool until the evacuation happens