Digestion and Digestive systems

The digestive system is the part of the body responsible for acquiring nutrients and expelling wastes. This semester we dissected seven different animals, observing a different digestive system in each animal. As the dissected animals progressed from more primitive to more complex, the digestive systems also increased in complexity. The first animal dissected was the earthworm, which has a fairly basic digestive system. Food is ingested by the earthworm through the mouth, and then it …

…of digestible material. The sectioning of the stomach allows for break down of food into smaller particles and added nutrient absorption. The addition of digestive glands allows for the secretion of digestive enzymes. The liver produces bile, which aids in the digestion of fats, while the pancreas secretes additional digestive enzymes into the intestine. The villi of the frog greatly increases nutrient absorption, and the convoluted intestinal tract of the pig allows greater nutrient extraction.