fetal pig dissection digestive system diagram

FETAL PIG DISSECTION DIGESTIVE SYSTEM DIAGRAM SKIN

The liver has been lifted to reveal the gallbladder.įigure 22. Duodenum, gallbladder, liver, lungs, large intestine, pancreas, small intestine, stomach. The appendix in humans is the evolutionary remains of a larger cecum in human ancestors.įigure 21. The cecum is large in herbivores but much of it has been lost during evolution in humans. It houses bacteria used to digest plant materials such as cellulose. The cecum is a blind pouch where the small intestine joins the large intestine. The spleen is an elongate, flattened, brownish organ that extends along the posterior part of the stomach ventral to (above) the pancreas. Lift the stomach and identify this light-colored organ. It extends along the length of the stomach from the left side of the body (your right) to the point where the stomach joins the small intestine. The pancreas is located dorsal and posterior to the stomach. Find the bile duct that leads to the small intestine. This structure stores bile produced by the liver. Lift the right lobe and find the gallbladder.

Locate the cecum, a blind pouch where the small intestine joins the large intestine. Find the posterior part of the large intestine called the rectum and observe that it leads to the anus. Identify the small intestine and large intestine. Using a probe, trace follow the esophagus to the stomach. You have already seen how the esophagus leads from the pharynx through the neck region. Esophagus, larynx, trachea, bronchus, and lungs. You should not remove these structures yet because you will need to identify the blood vessels later in the dissection.įigure 15. In the photograph below, the heart and blood vessels of the neck region have been removed so that the trachea can be seen more clearly. The large hard structure attached to the trachea is the larynx. The surrounding tissues have been separated to reveal the thyroid gland.Ĭontinue separating the tissue with a probe until the trachea and esophagus are exposed. The thyroid gland is darker and lies between the posterior ends of the two lobes of the thymus gland.įigure 14. Use a probe to separate the two lobes of the thymus gland and to further separate the musculature over the trachea.

Use the probe to peel away muscle tissue until the thymus gland on each side of the trachea is exposed.

FETAL PIG DISSECTION DIGESTIVE SYSTEM DIAGRAM SKIN

Hard palate, soft palate, glottis, epiglottis, and tongue.Ĭarefully, peel the skin away from the incision in the neck region using a blunt probe (a needle or the point of scissors will do if a blunt probe is not available). From the pharynx, it passes through the glottis to the trachea.įigure 12. The pharynx is the space in the posterior portion of the mouth that both food and air pass through. When breathing, air passes through the nasal passages to the pharynx. The hard palate and soft palate separate the nasal and oral cavities. The epiglottis projects up through the soft palate into a region called the nasopharynx. Open the jaw wide enough so that the glottis and epiglottis are exposed. You will need to cut through the musculature and the joint that holds the lower jaw to the skull. Use a scalpel to cut the sides of the mouth so that the bottom jaw can be opened for easier viewing (see figure 11). These two cuts will enable you to spread open the abdominal cavity. Cut completely through the body wall in the abdominal area but keep the cut shallow in the neck region.Ī cut is made on the side of the animal from the point just posterior to the diaphragm dorsally.

The flap of body wall that contains the navel can be folded posteriorly to reveal the internal organs of the abdomen.Įxtend a single cut along the midline of the ventral surface of the animal to about 2 cm. Your finished cut will be anterior to the navel and along each side of the navel. Continue cutting from the anterior end of this cut so that it resembles an upside-down U. Insert one blade of scissors through the body wall on one side of the umbilical cord and cut posteriorly to the base of the leg as shown in figure 6. Tie one front leg of the animal with a string that passes underneath the dissecting pan to the other leg.

Fetal pig dissection digestive system diagram