Fetal Pig Dissection Lab Report

Introductory
Dissecting animals helps students better understand the anatomy of, in this case, a fetal pig, and helps us prepare for what University has to offer, depending on what one will study. Purpose
The purpose of the fetal pig dissection was to understand the scientific process of dissection and gain hands-on experience of the internal and external anatomy of the fetal pig. In addition to this, the fetal pig dissection helps students better interpret the relative position and sizes of organs, as well relation between organ and organ system. Hypothesis

Gurjot, Manvir and I had hypothesized that the fetal pig’s internal systems should be slightly alike, due to the fact that pigs are on the same level food chain as us humans. Materials:
Safety goggles (opt.)
Plastic lab apron (opt.)
Non-latex gloves
Preserved fetal pigs
Dissecting tray
Antibacterial soap
String
Scissors
Scalpel
Measuring tape
Paper towels
dissecting pins
blunt probe

Basic diagram of sections of fetal pig
(Left)
Procedure
1. Use string to measure pig from tip of snout to base of tail. The table below determines age via length.

Length of String (cm)
Age of pig
0-10 cm
20 days
10-20 cm
30-35 days
20-30 cm
45-50 days
40-50 cm
55 days
100 cm
70 days
150 cm
80 days
200 cm
100 days
300 cm
120 days
2. Place fetal pig on back, exposing the dorsal surface. Then, tie the pig for ease of dissection therefore it willn’t move during dissection. 3. Determine sex of pig. Sex of pig can easily be determined through viewing posterior view of pig. If one sees the scrotal sac, he is a male. If one sees a genital papilla, she is a female. 4. To effectively expose the inner organs of the fetal pig, make 5 incision cuts: INCISION 1: 10-15cm incision in front of umbilical cord towards head. INCISION 2: Cut towards posterior surface.

INCISION 3: Cut towards lateral surface. May use scissors for lateral incision. INCISION 4: Cut towards posterior portion of abdominal cavity.
INCISION 5: Cut between thoracic and abdominal cavity.

*May want to feel for ribs when cutting INCISION 5.

Incisions for dissection of fetal pig
5. Expose abdominal cavity. This can be done by pulling apart flaps at INCISION 5. *You may want to use scalpel to cut through skin, and hold down skin through dissecting pins.

Diagram of fetal pig and organs of abdominal cavity

6. Locate liver and gall bladder.
Liver located near front of abdominal cavity.
Gall Bladder located underneath liver.
7. Locate stomach. Stomach located beneath liver, on left side of fetal pig. Stomach tends to appear hollow. Furthermore, the anterior portion of the stomach is in conjunction with the esophagus, whereas the posterior portion of the stomach is in conjunction with the duodenum. 8. Locate Pancreas. The pancreas is located toward the back wall of the abdominal cavity. It is a finger-shaped gland, and creamy white in colour. Moreover, the pancreas is best reached by lifting junction of stomach and small intestine. 9. Locate the spleen. The spleen is located on left side of fetal pig, found near outer curvature of stomach. 10. Remove stomach by cuts at junction with esophagus and small intestine, specifically, the duodenum. This can be done so using a scalpel. 11. When locating small and large intestines, observe the thing film that holds them together. This is known as the mesentery. Carefully snip away mesentery and unravel.

Thoracic and circulatory procedures
12. To expose thoracic cavity, fold back skin above thoracic cavity and hold back via dissecting pins for better view and dissecting. Thoracic cavity is area between incisions 3 and 5. 13. Locate the heart. The heart is found between the two lungs and protected by rib cage. Furthermore, the heart is surrounded by thin, transparent membrane called pericardium. Remove pericardium carefully to isolate heart. Locating major vessels of the heart

Inferior vena cava: Runs from liver and lower part of body to right side of heart. Empties into right atrium. Superior vena cava: Runs from upper body of pig to right side of heart. Empties into right atrium. Pulmonary trunk: Begins at right ventricles. Transports deoxygenated blood to lungs. Aorta: Largest artery in circulatory system. Branches to transport blood to all major organs. Aortic arch: Part of aorta that arises from left ventricle. Two major vessels come from aortic arch: Bracheocephalic trunk: Splits to send to right forelimb + head. Left subclavian artery: Supplies left forelimb. 14. Using the blunt probe, you can discover 4 chambers of heart. Locating the right chamber via the diagram below. It is visible within the eye.

Locating the left atrium is also visible within the eye. You will notice several veins at left atrium, known as the pulmonary veins. Also, isolate pulmonary veins from heart via scissors. Locate the aorta coming off left ventricle and separate from heart via scissors. Then, locate pulmonary trunk arising from right ventricle and separate from heart via scissors. Finally, remove heart from thoracic cavity by teasing away connective tissue. 15. After so, make incision that separates left side and right side of heart. 16. Locating the lungs: Lungs are very visible with eyes. Lungs are relatively large due to the fact that the bronchial tree is contained within them. Dorsal view of heart in the fetal pig

Observations:

Fetal Pig Observation Questions
All questions within textbook procedure answered below.
1. With the chart given above under procedure 1, we determined that our fetal pig was approximately 55 days, as the length of the fetal pig was 37 cm long. 3a. The function of the umbilical cord is to transport nutrients to the fetal pigs from the mother pig.

3b. Two blood vessels were seen within the umbilical cord.
4. The sex of our pig, Gurjot Jr., is male.
5. There were 4 toes on each foot, therefore 16 toes total. Also, it was positioned; front feet curled inwards and back feet are flat (normal pos.).

6. Yes, our fetal pig contained hair on his chin, had eyelashes, and had a tongue as well. 9. The gallbladder connects to the top left portion of the small intestine. 10. As we lifted the small intestine, we noticed the large intestine. Also, the advantage of having mesentery film is that it keep one’s intestines together. As I, Saadaf made an effort to fully isolate the small intestine to measure it’s length, I had to cut through the mesentery to fully isolate the small intestine from itself. 11. Vital substances the pancreas provides us with is insulin. Insulin makes our body’s cells absorb glucose from the blood. The glucose is stored in the liver and muscle as glycogen and stops the body from using fat as a source of energy. 12. The function of the spleen is that it is a blood reservoir; it stores and recycles blood for future use. For example, when one is injured and has a cut, the spleen will supply it with blood.

14. Length of small intestine unraveled: 2.9m
The small intestine is different from the large intestine as they have different functions. The small intestine’s major function is to absorb all nutrients from food via villi and then send to the large intestine to excrete as waste. As mentioned in the previous sentence, the large intestine majorly only transports remaining waste and whatnot through the anus. However, if the small intestine did not fully absorb all nutrients, the large intestine can absorb nutrients as well, as it too contains vill. 16. The fetal pig’s heart is surrounded by pericardium, similar to the mesentery of the small intestine and can be easily cut via scissors or forceps. However, forceps are the best tool to accomplish this due to the fact that they are effective when isolating small objects and skin.

20. As we compared the size of a ventricular and atrial wall, we observed that the atrial walls are thin and elastic whereas the ventricular walls ware thick and more muscle-like. 21. Yes, there is difference in the sizes of both lungs; the right lung is larger than the left due to the fact that the heart is mostly on the left side of the lungs., and must leave space for the heart. 22. The left ventricle contains more muscle than the right ventricle because the left ventricle must pump blood to the aorta, which the aorta then transports blood to the entire body. The right ventricle must pump blood to the pulmonary artery, which the pulmonary artery then transports blood to the lungs to oxygenate them. 23. The lungs of the fetal pig feel spongy because they are made up of millions of alveoli, giving it a spongy feeling. 24. The function the cartilaginous rings of the trachea is to keep the trachea open when breathing. Without cartilaginous rings in our trachea, our trachea would collapse.

Reflections:
Saadaf’s reflection…
The fetal pig dissection was without a doubt a tremendous experience overall, as it gave me hands-on experience, collaborative skills, and even inspiration for that matter. To begin, let’s go in depth with hands-on experience. Typically, I and many prefer hands-on tasks. This is because you better understand what you are doing, and the concept behind it. In this case, the hands-on experience of dissecting a fetal pig better helped me understand internal systems and the functions of the organs. Collaborative wise, this helped me because I tend to prefer working by myself, therefore when the time comes to work co-operatively, I have learned how to quickly assign tasks to students where everyone receives a fair and equal amount of work.

However, the fetal pig dissection in fact did not even feel as if it was “work.” I truly really did enjoy cutting up and discovering what lies beneath the skin of our bodies, and the numerous functions our body must perform in order to keep us going every day. As I had mentioned pros above, any cons to this dissection project would be the mass murder of killing the pigs to educate SBI 3UO students on internal systems. Due to this, I would like to say that all my respect goes to the murder of the fetal pigs, to educate students and I. However, I am Muslim and do not eat or like pigs as they are swine to me. Anyways to conclude, I have always been inspired to major in a biology specific area/course since I was a young man, and projects such as the fetal pig dissection make me even more inspired to major in courses such as forensics or biomedical and brings me a step closer to achieving my destiny.