The Digestive TrackThe BIG MAC is placed in the mouth. The bread is mainly starch, the specialsauce is mainly fat, lettuce, pickles, and onions are niacin.
The beef pattiesare protein,and cheeseis a form of calcium, fat, and protein. The piece of the BIG MAC is placed in the mouth and chewed, the starch isbeing digested by saliva. The starch becomes a kind of sugar which is used as anourishment for the cells. Saliva changes food to a form that can be used bythe body called enzymes. The burger is swallowed and passes into the esophagus. This is the muscular tube that contracts along its length to push the food downinto the stomach.
In the alimentary canal the meat and special sauce is beingabsorbed. The fat in the sauce is used for energy and the protein in the meatis used to build muscles, the lettuce, pickles, onions are also absorbed. In the stomach, which is a muscle, the food is churned about while digestivejuices pour int from glands in the stomach wall. Eventually, the the churningaction moves food out of the stomach and into the small intestine.
The levercontributes to this digestive process by secreting into the small intestine, aliquid called bile. The pancreas secretes pancreatic juice which further aidsin dissolving food. The small intestine undergoes continual muscular contractions calledperistalses. This action pushes food into the large intestine. This surface ofthe small intestine has a large number of threadlike projections called villi. The digested, liquified food is absorbed through the villi, and passes intocapillaries that are inside the villi.
Now the food is in the bloodstream. Notall parts of the BIG MAC can be digested. Those parts which are indigestible passthrough the large intestine to its lower part, called the rectum. Eventually,the indigestible food is eliminated from the rectum through the anus.
This isthe complete teck that the BIG MAC follows when it is eaten.
