carcinogen for humans. Anatomy The anatomy of a fetal pig is similar to that of the adult pig in various aspects. Systems that are similar include the nervous, skeletal, respiratory (neglecting the under developed diaphragm), and muscular. Other important body systems have significant differences from the adult pig. Circulatory system There are only a few differences between the circulatory system of an adult pig and a fetal pig, besides from the umbilical arteries and vein. There is a shunt between the wall of the right and left atrium called the foramen ovale. This allows blood to pass directly from the right to left atrium. There is also the ductus arteriosus which allows blood from the right atrium to be diverted to the aortic arch. Both of these shunts close a few minutes after birth. Digestive The monogastric digestive system of the fetal pig harbors many similarities with many other mammals. The fetal pig's digestive organs are well developed before birth, although it does not ingest food. These organs include the esophagus, stomach, small and large intestines. Mesenteries serve to connect the organs of the fetal pig together. In order for digestion to occur, the fetal pig would have to ingest food. Instead, it gains much needed nutrition from the mother pig via the umbilical cord. In the adult pig, food will follow the general flow through the esophagus, which can be located behind the tracheae. From the oral cavity, the esophagus leads to the stomach, small intestine, and large intestine. Other organs developing during fetal pig development such as the gallbladder, pancreas and spleen are all critical in contributing to the overall flow of the digestive system because they contain digestive enzymes that will perform chemical digestion of food. After food is digested and nutrients are absorbed, the food follows through the large intestine and solid wastes are excreted through the anus. In the fetal pig however, the metabolic wastes are sent back to the mother through the umbilical cord where the mother excretes the wastes. Other remaining wastes remain in the fetal pig until birth. Then The oral cavity of the fetal pig begins developing before birth. The tongue's taste buds, located in the enlarged papillae, facilitate food handling after birth. These taste buds develop during fetal development. Adult pigs have up to 15,000 taste buds, a much larger number than the average human tongue, which has 9,000. The