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On Thursday April 10th 2014, the AP Bio class dissected pigs to observe their organs and body structures. We each got one fetal pig per three people. We choose to use pigs because they have similar structures and systems as humans. A fetal pig is a pig that has not been born yet. Our fetal pig was male. I learned at a vet summer program that pigs have a gestation period or are pregnant for three months, three weeks, and three days. The pigs we used were towards the end of their gestation period. One person was the main dissector and the other two were the writers, readers, and photographers.
When dissecting the pig, we looked at the digestive system, respiratory system, circulatory system, excretory system, and the reproductive system.
We first dissected the umbilical cord and investigated the inside of the cord. We noticed that there were veins and arteries inside the umbilical cord. Veins are bigger in diameter then arteries. The pig had been injected with dyes turning the veins and arteries either blue or red. I learned that the arteries would carry away CO2 and other wastes, away from the pig inside the womb. Veins would carry oxygen and other nutrients toward the fetus. We also noticed that even though our pig was a male, he had nipples. We learned that they are called papillae. On our pig there were 14 papillae. These papillae are used to deliver breast milk to piglets after they are born.
We then dissected the abdomen and observed the organs in the abdomen. The largest organ in the abdomen is the liver. The liver detoxifies blood, produces bile, stores vitamin and iron, stores glucose, breaks down insulin and hemoglobin, converts ammonia to urea, an destroys old red blood cells. Under the liver is the gall bladder. Unlike the liver, the gall bladder is not a gland because unlike a gland, the gall bladder stores instead of secreting. The strip of tissue that lines the body’s wall is called the spleen. The spleen purifies blood and helps the immune system identify and attack foreign antigens. The digestive system includes the liver, stomach, spleen, pancreas, and intestines.
Then, we looked at the respiratory and circulatory system. We looked at the heart, veins, arteries, and lungs. I never realized how much work went into breathing. The execratory system came next, which includes the bladder and the kidney. We finished with the reproductive system. Because we had a male, we had to look at a different pig that was a female to look at the ovaries. In the male we were able to see the urethra, scrotum, and testes.
All in all this was a great experience and I’m glad we were able to do the dissection. We got to see all the organs and how they relate to each other up close and personally. Seeing the organs in real life was much better then looking at a drawing because we got to really see how the body works.