A&P Fetal Pig Report
Mullins 7/15/10 142L Formal Lab Report one “Dissection of the Urinary and Reproductive Systems of the Fetal Pig” Introduction The Fetal Pig is left over from last semester’s A&P Lab I and is being recycled for the second A&P lab. During this dissection session my lab partner and I did two dissections. The first one of the Urinary system, and the second of the Reproductive system. The fetal pig was in a zip lock bag, wrapped with wet paper towels and its own skin. Methods We wore gloves, and removed the fetal pig from its wrappings, placing it into a dissection pan. The tissue was gray in the fetal pig.
The fetal pig was previously dissected, so we could see the Kidneys, Urinary bladder, and some of the reproductive organs right away. The rest of the dissection process took a lot of patience, which my lab patience, and care not to cut important structures. Results The first thing we were instructed to do was remove the intestines, which was done. My lab partner removed more fat and connective tissue, and flushed the pig with water so we could see the structures better. With help from our instructor we located the Adrenal glands, which were kind of grainy and located on the anteromedial surface of each kidney.
They were hard to find, and had no color to them as stated in the lab manual. The Renal Artery was red, and easy to see. The Renal Vein was harder to locate, and not as easy to find as the lab manual stated. It was located in the area of the right Kidney. The left kidney was larger than the right kidney. The right kidney did not take the dye in as much as the structures of the left kidney and surrounding area. We were able to trace the Ureters posteriorly along the dorsal body wall where they turned ventrally to enter the fetal urinary bladder. The urinary bladder was cut through to examine the urethral exit.
I could not see the internal sphincter. My lab partner used a blunt probe to push aside excess tissue or just removed it. Tracing the urethra as it exits from the bladder ti its terminus in the urogenital sinus. There were no female pigs available for comparison. Part two was the dissection of the reproductive system of the fetal pig. Again orifice was visible on the ventral body surface just posterior to the umbilical cord, which is called the external urethral orifice. Cutting through the skin of the orifice, the distal end of the penis was exposed.
Carefully cleaning, my lab partner exposed the left and right ductus deferens, which was enclosed in the spermatic cord. We followed the urethra superiorly until we found these. Carefully cutting, we found the spermatic cord. Tracing the spermatic cord posteriorly through the inguinal canal into the scrotum, we were able to identify the scrotal sac exteriorly on the ventral body surface anterior to the anus. We exposed the testis, but they were not well formed and hard to find and see. Longitudinal cuts were made through the testis and epididymis, where there was evidence of several tubes visible with the naked eye.
We were unable to identify or look at the reproductive structures of a real fetal pig because there were none available. Discussion In this lab we dissected the fetal pig to see how the different structures of the urinary and reproductive organs looked. The exercise asked us to compare how these structures were similar in function and/or different in structure or function from human anatomy. The urethra, ovaries, uterine tubes, testes, epididymis, and inguinal canal are basically the same in the fetal pig and human.
Humans and pigs have different uteruses simplex versus bicornate. The pathway of urine is different in a fetus versus adult. In the female pig, there is only one opening for the urine and the vagina, whereas in the female human there are two separate openings, vagina and urethra. Below are my attempts to draw and label the dissections of the male and female fetal pig. References Marieb, E. N. & Mitchelle, S. J. (2011) Human Anatomy and Physiology Manual 10th edition. Benjamin Cummings, Boston pgs 741-748 Retrieved from on 7/15/10 www. biologyjunction. com/fetal_pig_dissection. htm