Fetal Pig Dissection

External Anatomy 1. Determine the sex of your pig by looking for the urogenital opening. (this is where liquid waste (urine) exits the body) 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.  this is a flap of tissue covering the opening of the vagina. Both males and females have rows of nipples, and the umbilical cord will be present in both. What sex is your pig? _________ Now that you know the sex, name your pig!

2. Make sure you are familiar with terms of reference: anterior, posterior, dorsal, ventral.

Anterior: Near the front or near the head Posterior: Near the back or near the hind end Dorsal: Upper side of back Ventral: Underside of an animal

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.

Feel the edge of the mouth for teeth. Does your fetal pig have teeth? Like all young mammals, fetal pigs have milk teeth (baby teeth) that are later replaced by permanent teeth.

Are humans born with teeth? Hint: Teeth are aimed to bite and grind food particles for further digestion Baby teeth in humans normally tends to appear around 6 months in age, although some babies are born with one or more visible teeth, known as natal teeth.

Gestation the carrying of young in the uterus from conception to delivery

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? __________________ They are born shut, and will open within 1-5 minutes of birth!

Masseter Muscle

External Anatomy- label

Internal Anatomy of Fetal Pig In this activity, you will open the abdominal and thoracic cavity of the fetal pig and identify structures. Remember, that to dissect means to "expose to view" - a careful dissection will make it easier for you to find the organs and structures. Be sure to follow all directions.

The Incision Place your fetal pig in the dissecting pan ventral side up. Use string to "hog-tie" your pig so that the legs are spread eagle and not in your way. Use a scalpel to cut through the skin and muscles according to the diagram. Do not remove the umbilical cord. In the first section, you will only examine the abdominal cavity (the area below the ribcage).

Umbilical Vein After completing the cuts, locate the umbilical vein that leads from the umbilical cord to the liver. You will need to cut this vein in order to open up the abdominal cavity.

Your pig may be filled with water and preservative, drain over the sink if necessary and rinse organs. Locate each of the organs below, check the box.

Organs: Diaphragm

Organs: Liver and Gall Bladder

Organs: Stomach and Esophagus

Organs: small intestine

Organs: Pancreas

Organs: Spleen

Organs: Large Intestine

Organs: Kidneys

Label: Organs in Abdominal Cavity 1._____esophagus___ 2. _____liver_______________ 3. _____gall bladder_________ 4. ____bile duct___________ 5. ____stomach____________ 6. ____duodenum_____________ 7. ____pancreas______________ 8. ____small intestine_______ 9. ____spleen_____________ 10. ___cecum_____________ 11. ___large intestine__________ 12. ___rectum_____________ 13. ___umbilical arteries__________  

Identify the organ (or structure) 14. Liver Largest organ in the body. 15. Gall bladder Stores bile, lies underneath the liver. 16. Rectum This opens to the outside of the pig, or the anus 17. Diaphragm Separates the thoracic and abdominal cavity; aids breathing. 18. Small intestine Made up of the duodenum and the ileum. 19. StomachThis organ churns and breaks down food. 20. Bile duct Empties bile into the small intestine from the gall bladder. 21. Kidneys Removes harmful substances from the blood. 22. Pancreas Bumpy structure under the stomach; makes insulin 23. Spleen This stores blood and is not part of the digestive system.