Human Digestion Sci 220

557 Words3 Pages
Identify factors that affect the amount of time it takes for food to travel through the digestive tract - Explain how digestion occurs in mouth, stomach, small intestine, large intestine – The body starts the digestion process before food even enters the mouth. As soon as something that smells good hits the nose, the body starts to salivate and produce stomach acids. Once it enters the mouth, the body gets to work. All three salivary glands (the parotid, sublingual and submandibular) produce saliva which begins to chemically break down the food. The tongue and teeth move the food around, mixing it with the saliva, with all 32 teeth tearing and crushing it to break it down further into a softer composition called a bolus. During the swallowing process, the epiglottis blocks the air passage to prevent food from going into the lungs. Once swallowed, the esophagus movies it by way of peristalsis, or squeezing and relaxing of the muscles, down into the stomach. The stomach acts as a holding tank for the food while it mixes further with gastric juices such as enzymes and acids from its lining, to break down the bolus into a thick creamy substance called chyme. After turning into chyme, it is sufficiently processed enough to release into the small intestine. This is where the major digestion occurs, as well as where the water, vitamins, minerals and other nutrients are absorbed into the body. All that remains is a liquid substance which moves onto the large intestine also known as the colon. This is a six foot long muscular tube (hence the term large intestine) which connects the small intestine to the rectum. It is responsible for processing the waste and turning it into stool. This stool is sent on to the rectum, which connects the colon to the anus and serves as a holding place for the stool before it goes to the anus for secretion. The anus controls the stool,
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