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Fetal Pig Dissection Resources from Starts At Eight. Weather you are actually dissecting a pig or planning to learn about it virtually, I have compiled a list of our favorite fetal pig dissection resources. Includes video, photos, detailed diagrams, FREE Printables and more! Great for homeschooling, high school biology, or just for fun! Fetal Pig Model This 20-inch long fetal pig is a life-size model composed of a flexible plastic. It features all of the internal organs, major arteries and veins found along the body cavity, head and neck. The heart, lungs, stomach, liver and intestines are removable as a single unit, and one kidney is.
Learning Objectives
- Learn about the anatomy of the pig as an example of a vertebrate mammal
- Identify structures on the pig and know their functions
- Identify structures that are a part of the digestive system, respiratory system, circulatory system, reproductive system, and excretory system
- Compare pig anatomy to human anatomy
Procedure
Access the page “Reading: Fetal Pig Dissection.” The pig may or may not be injected with dye. Follow the steps in the handout to view the external pig anatomy.
Questions
- Based on the external anatomy is your pig male or female? How can you tell?
- Can you locate any hair on your pig, a common characteristic of mammals? Where is there the most hair?
Follow the steps in the handout to cut open the pig beginning with the mouth. Make sure you can locate the following structures in the mouth region:
- Glottis
- Epiglottis
- Hard and soft palate
- Pharynx
- Trachea
Question
- What do the hard and soft palate separate?
Cut into the neck region. Make sure you can locate the following structures:
- Trachea
- Thymus
- Thyroid
- Esophagus
Question
- Is the trachea in front of or behind the esophagus?
Cut into the thoracic cavity beneath the rib cage. Make sure you can locate the following structures:
- Heart
- Lungs
- Bronchi
- Diaphragm
Questions
- How many chambers does the pig heart have?
- How does the size of the pig lungs compare to the size of the frog lungs you dissected previously?
- What role does the diaphragm play in respiration?
- What cavity contains the lungs?
- What cavity contains the heart?
Focus next on the abdominal cavity. First look at the digestive system organs. Make sure you can locate the following organs:
- Stomach
- Spleen
- Liver
- Gallbladder
- Small intestine
- Large intestine
- Pancreas
Questions
- What is the function of the liver?
- What is the function of the gallbladder?
- What type of digestion occurs in the stomach?
- Name the three sections of the small intestines in order.
- Name one process that occurs in the large intestine.
- Which digestive organs located in the abdominal cavity are considered to be accessory organs?
Also in the abdominal cavity you will find the excretory system organs. Make sure you can locate:
- Kidneys
- Bladder
Finally in the abdominal cavity are the reproductive organs. If you have a female pig look at another group’s male pig and vice versa. You should be able to find:
- Testes (male)
- Uterus with horn (female)
- Ovary (female)
The arteries and veins are challenging to identify, especially if the pig is not injected with dye. Arteries carry blood away from the heart. Veins return blood to the heart. Try to identify the following:
- Aorta
- Pulmonary artery
- Coronary arteries
- Jugular vein
- Carotid artery
- Renal artery
- Renal vein
Questions
- Where does the renal vein transport blood?
- Where does the pulmonary artery transport blood?
View the human torso model on your bench. Locate the same organs you found above on the fetal pig.
Questions
- List three similarities between the pig internal anatomy and human internal anatomy.
- List three differences between the pig internal anatomy and human internal anatomy.
- Share
A fetal pig is a great choice for dissection because the size of the organs make them easy to find and identify.
It is also a very exciting dissection because, like sheep and their organs, the internal anatomy is similar to humans! It is fascinating to see how all the organs fit and work together. Use this guide to help you dissect a preserved fetal pig, or just look at the labeled pictures to get an idea of what the organs look like. If you do the dissection yourself, you will need a dissecting tray and some dissecting tools, or buy our complete Fetal Pig Dissection Kit.
Fetal Pig Dissection Overview
External Anatomy
1. Most of the pig’s external features are familiar to you – ears, nose, eyes, etc. On the belly you will see the umbilical cord which connected the fetal pig to its mother’s placenta. On either side of the umbilical cord you may see mammary papillae, little nipples that will turn into teats in female pigs.
2. Determine if your specimen is male or female by looking closely at the umbilical cord area. If the pig is male, it will have a small urogenital opening immediately behind the umbilical cord. If the pig is female, the urogenital opening will be just behind the anus under the pig’s tail. Only the female has two openings beneath the tail.
Oral Cavity
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1. Using your dissecting scissors, cut through the jaw bones at the corner of the pig’s mouth. Cut far enough so that the bottom half of the jaw can almost touch the pig’s chest.
2. Open the mouth as far as you can. Use the labeled picture to identify the feathery papillae (taste buds) on the edges of the tongue, the ridged hard palate in the roof of the mouth with the smooth soft palate behind it, the sharp teeth near the front of the mouth, and the epiglottis, which covers the opening of the trachea (windpipe) so food cannot enter.
Body Cavity Incisions
1. Tie a string around one of the pig’s forelegs. Pass the string under your dissecting pan and tie it to the other foreleg. Stretch the string tightly so that it will hold the pig’s legs apart. Repeat with the back legs.
Click image for full-size pdf |
2. Use your fingers to probe the chest area of the pig. You should be able to feel the hard sternum (breastbone) and the tiny ridges of the ribcage. Keep moving down until you feel the bottom edge of the rib cage; this is where the diaphragm separates the thoracic cavity from the abdominal cavity. This point is marked with an X in the illustration.
3. Make an upside-down V incision starting at X, as you see in the illustration. Start the cut with a scalpel, then continue it with dissecting scissors. You want to cut through the skin and the muscle, but if you cut too deep you will damage the internal organs. Use forceps to hold the tissue away from the organs as you cut. Carry the incision all the way to the pan.
4. Start the second incision at X and carry it straight down almost to the umbilical cord. Cut a semi-circle around the umbilical cord on each side. Make the third incision just above the hind legs and carry it all the way down to the pan.
5. Now lift up the flaps of skin and peel them back so they lay flat on the pan. There may be some connective tissue or membranes attaching the muscles to the underlying organs. Cut carefully through this so you can lift the flaps back. The abdominal cavity is now exposed.
6. Beginning at X again, make the fourth incision up through the chest. Use the scissors to cut through the rib cage and the sternum. When you reach the midpoint between the forelegs, make another incision down to the pan. Go back to the diaphragm area and use a scalpel to cut the wall of the body cavity away from the diaphragm. The diaphragm should remain intact, but now the rib cage can be pulled back and pinned to the pan, exposing the thoracic cavity.
7. Make the last two incisions to expose the neck area.
Abdominal Cavity
1. The largest organ in the abdominal cavity is by far the liver, just below the diaphragm (the flap of muscle separating the abdominal from the thoracic cavity). Notice the umbilical vein connecting the umbilical cord with the liver. Cut this vein so you can lay the umbilical cord back between the pig’s hind legs.
2. Use the labeled pictures to find the following organs:
Click for full-size pdf |
Click for full-size pdf |
- Liver – the liver is the large black/brown multi-lobed organ at the top of the abdominal cavity.
- Stomach – the pig’s stomach is located on the right side, tucked under the liver.
- Spleen – the spleen is not part of the digestive system; it helps filter the pig’s blood. It is a thin finger-like organ lying on the stomach and matching it in color.
- Small Intestine – the small intestine is a large mass of coiled tube that fills the bottom half of the abdominal cavity. It is held in place by tissue called mesentery. Lift up a section of the intestine and pull it tight – the mesentery is the thin tissue filled with blood vessels.
- Large Intestine – the large intestine’s big coils look fused together. It sits to the right of the small intestine, just below the stomach.
- Kidneys – carefully move the intestines aside to see the large bean-shaped kidneys (one on each side) covered in a shiny membrane.
- Urinary Bladder – between the blood vessels in the umbilical cord is the long, flat bladder.
- Gall Bladder – gently lift the liver to see the round gall bladder imbedded in the under side of the lobe that the umbilical vein was attached to.
3. If your specimen is a male, you will find long brown tubes on either side of the folded-back umbilical cord. At the end of these tubes are the rounded testes. A whitish sack attached to the testis is the epididymis, which stores sperm cells. If your specimen is female, you will find the ovaries at the base of the umbilical cord/urinary bladder. Directly below the ovaries you will see a flap of tissue called the horns of the uterus; this part leads to the main body of the uterus.
Thoracic Cavity
1. The thoracic cavity is protected by the rib cage and contains the lungs and heart. Use the labeled picture to find the following organs:
Click for full-size pdf |
- Lungs – the lungs have multiple lobes and are found on either side of the heart.
- Heart – the heart is encased in a shiny pericardial membrane; carefully remove this with your scissors or a teasing needle. Gently lift the lungs so you can see the dark tissue called auricles above the atria (upper chambers of the heart).
- Esophagus – gently push the heart to the side to see the shiny white tube traveling down behind it. This carries food to the stomach.
- Trachea – extending up from the lungs is the ridged ‘windpipe,’ or trachea.
- Larynx – at the top of the throat the trachea bulges out into the larynx, or voice box.
Fetal Pig Dissection Resources
To study the pig in more detail, go to this Virtual Pig Dissection. It covers all the body systems and includes quizzes to test your knowledge!
Label the Anatomy of a Fetal Pig
Print out these PDFs and fill in the labels to test your knowledge of fetal pig anatomy.
- Internal anatomy: label the middle section
- Internal anatomy: label the top section
See our other free dissection guides with photos and printable PDFs. Click here.
What other users say:
Absolutely Fantastic!
My students thoroughly enjoy completing the dissection projects. I highly recommend these specimens for anyone interested in learning more about the anatomy of specific organisms. -Sandi
My students thoroughly enjoy completing the dissection projects. I highly recommend these specimens for anyone interested in learning more about the anatomy of specific organisms. -Sandi