Dissection of the Respiratory System of the Fetal Pig Inferior to the Larynx
Dissection is an art. We must carefully and accurately dissect the pig so we can identify all important parts. We must use caution when carrying and cleaning sharp dissection tools. Dissection must help us to get to figure out specific parts of the organ that we need. In general, dissection in biology lab will help us to see of how all the systems get together in an entire organism. We will get to see how they are all arranged spatially. We will also get a better idea of the texture of many organs that make up the pig’s system.
I chose to do the respiratory system because it is one of the easiest to describe, but nothing in the oral cavity because it’s not very instructive, and we never do it in lab. Here are my twelve instructions for a fetal pig dissection. 1. Retrieve a fetal pig In this first method, the great caution is recommended. It is required to retrieve a fetal pig from the bucket with large tongs, being careful to drain as much preservative as possible. 2. Stabilize the pig Place the pig ventral side up on a medium-sized dissection tray. Secure the pig to the tray using twine.
Tie the twine to one of the pig’s front hooves. Wrap the twine behind the dissection tray and secure the second hoof. Do the same for the back hooves. In other words, place the pig on its back and tie it with its arms and legs stretched apart using twine. 3. Start of the dissection Beginning immediately superior to the umbilical cord, use large dissection scissors to make a small, V-shaped incision into the body cavity. Using the blunt side of the scissors, extend this incision in a U shape inferiorly around the umbilical cord to the pelvis and superiorly through the right side of the sternum to the clavicle.
We can also say make a cut in the wall of the abdomen just above the umbilical cord. Extend this cut downwards in a U shape around the umbilical cord toward each hind leg and upwards through the rib cage to the collar bone. 4. Lateral incision To fully open the body cavity, make perpendicular incisions laterally just superior to the hind legs, just inferior to the front legs and just inferiorly to the rib cage, between the diaphragm and the liver. Peel back the walls of the abdomen to reveal the abdominal cavity.
In other words cut perpendicularly to the mid-line incision just above the hind legs, just below the front legs and just below the rib cage. 5. Caution to not damage the diaphragm In order to avoid damaging the diaphragm when opening the thoracic cavity, cut the diaphragm away from the rib cage so that it lies over the liver. Gently, but firmly use both hands to crack open the rib cage. 6. Expose the larynx and trachea Using tweezers and a scalpel, carefully cut away the muscles of the neck to expose the larynx and trachea.
You may remove any overlying blood vessels, as these are not the focus of this dissection. If possible, extend your dissection superiorly to the hyoid bone. In simplify words, for the last sentence: Extend your dissection as far up as the hyoid bone. 7. Remove the top of the cricoid and thyroid Using a scalpel cut along the frontal plane through the cricoid and thyroid cartilages to reveal the vocal fold. Remove the top of the cricoid and thyroid cartilages to reveal the vocal cords. 8. Remove the thymus and pericardium
Using tweezers, remove the thymus and pericardium from the top of the heart. Lift the heart up out of the body cavity and remove it from the major arteries and veins using small dissection scissors. 9. Follow down the left and right primary Follow the path of the trachea inferiorly to the apical and primary bronchi. Following down the right and left primary bronchi, carefully shred the lung using a blunt probe to reveal the secondary bronchi. In other words follow the path of the trachea downwards to the apical and primary bronchi.
Following down the right and left primary bronchi, carefully shred the lung using a blunt probe to reveal the secondary bronchi. 10. Identifier the respiratory structures After identifying all of the respiratory structures, cover the abdominal and thoracic cavities with the folds of skin and muscle created in the first incisions. Slip the twine off of the ends of the dissection tray without removing it from the hooves so it can be reused to secure the animal in subsequent dissections. 11. Save the pic dissected
Mark a zip top bag with your section and table number. Place the pig in the bag with a little of the preservative from the dissection tray to keep it moist. Seal the bag and place it in a storage bin. 12. After the dissection Throw away any dissection waste in the regular trash. Clean the tabletops, dissection trays and instruments with soap and warm water. Thoroughly dry all instruments to ensure they do not rust. I also included some pictures from the lab manual so you’d have a visual of what I described.
(The vocal cords picture is from a cat, but the idea is the same). I gave the twelve most parts of how we dissect a pig. Dissection of the Respiratory System of the Fetal Pig Inferior to the Larynx is not necessary the best, but it is so easy to understand it. I choose the respiration system because it is also one the easier one to describe. Note that any pig dissection in a laboratory designed to be useful for a research or practical courses. So, it is necessarily required to do well and also clearly to present the various organs.