External Anatomy
1. Determine the sex of your pig by looking for the urogenital opening. On females, this opening is located near the anus. On males, the opening is located near the umbilical cord.
If your pig is female, you should also note that urogenital papilla is present near the genital opening. Males do not have urogenital papilla.
Both males and females have rows of nipples, and the umbilical cord will be present in both.
2. Make sure you are familiar with terms of reference: anterior, posterior, dorsal, ventral. In addition, you'll need to know the following terms
Medial: toward the midline or middle of the body
Lateral: toward the outside of the body
Proximal: close to a point of reference
Distal: farther from a point of reference
3. Open the pig's mouth and locate the hard and soft palate on the roof of the mouth. Can you feel your own hard and soft palates with your tongue?
Note the taste buds (also known as sensory papillae) on the side of the tongue. Locate the esophagus at the back of the mouth. Feel the edge of the mouth for teeth. Does the fetal pig have teeth? ________ Are humans born with teeth? ___________
Locate the epiglottis, a cone-shaped structure at the back of the mouth, a flap of skin helps to close this opening when a pig swallows. The pharynx is the cavity in the back of the mouth - it is the junction for food (esophagus) and air (trachea).
4. Gestation for the fetal pig is 112-115 days. The length of the fetal pig can give you a rough estimate of its age.
11mm - 21 days
17 mm - 35 days
2.8 cm - 49 days
4 cm - 56 days
22 cm - 100 days
30 cm -- birthHow old is your pig? _______________
5. Observe the toes of the pig. How many toes are on the feet? ___________________
Do they have an odd or even number of toes? _________________
6. Observe the eyes of the pig, carefully remove the eyelid so that you can view the eye underneath. Does it seem well developed? Do you think pigs are born with their eyes open or shut? __________________
7. Carefully lay the pig on one side in your dissecting pan and cut away the skin from the side of the face and upper neck to expose the masseter muscle that works the jaw, lymph nodes, and salivary glands. The salivary glands kind of look like chewing gum, and are often lost if you cut too deeply.
**Make sure you know the locations of all the bold words on this handout**