Fetal Pig Dissection

Videos

External Pig Anatomy

1. Obtain a Carolina’s Perfect Solution® pig, and lay the pig on its side in the dissection pan.
2. Determine the age of your specimen. Run a piece of string from the tip of the nose, along the curvature of the body, to the base of the tail. Measure the length of the string, and use the table below to help find the specimen’s approximate age.



Length of Specimen (Centimeters)	Approximate Age (Days from Fertilization)
4 cm	56
20 cm	75
25 cm	100
30 cm	112–115 days



3. Identify the following external features of the pig:
1. Nares (nostrils)
2. Tongue
3. Eyes
4. Pinnae (ears)
5. Umbilical cord
6. Teats





4. Determine the pig’s gender.
1. A female will have a urogenital opening and labia; these structures come together beneath the anus to form a small projection called the genital papilla.
2. A male pig will possess a urogenital opening, for the penis, nearer the umbilical cord. Depending on its development, a male also may have a sac of skin beneath the anus and between the hindlegs, the scrotum.

Internal Pig Anatomy

1. Position the pig in the dissection pan with its ventral surface up.
2. Secure the pig to the dissection pan. Intertwine 2 rubber bands in a figure 8 shape. Stretch the rubber bands under the pan, and loop the ends around the forelegs and hindlegs of the specimen to hold the pig in place.
3. Using a scalpel, follow the directions in this step, making the incisions indicated by the dotted lines in the figure below. Initial cuts should be shallow, cutting only through the skin. After making the initial incisions, cut deeper through the muscle tissue.
1. Begin at the throat and make an incision along the midline of the chest toward the umbilical cord.
2. Cut around the umbilical cord, making an upside down, U-shaped incision. Extend these cuts, in parallel, to the pubic region.
3. To reveal the abdominal organs, make 2 lateral incisions—one along the base of the ribcage and another at the hindlegs. Fold back the flaps of skin to expose the internal organs.
4. To open the thoracic cavity, cut away the ribs on either side of the rib cage and completely remove the chest plate.

4. Identify the major organs in the abdominal and thoracic cavities:

1. Liver
2. Stomach
3. Spleen
4. Large intestine
5. Small intestine
6. Heart
7. Lungs

5. Fold the liver and stomach upward to expose the gallbladder and the pancreas.
6. Remove the entire digestive tract to view the kidneys.
7. Follow all cleanup and disposal instructions.