Fetal Pig Dissection Manual

Procedure

Part 1 – External Anatomy

• Identify and record the 4 main body segments
• Examine the head of your pig
• Note the eyes. Each eye is protected by three eyelids! The third eyelid is the nictitating membrane – a small mass of tissue in the corner of each eye.

Part 2 – Internal Anatomy

• Be careful when dissecting your fetal pig.
• Only remove organs that you are asked to remove. Make superficial incisions before cutting deeper.

Dissection set up

• Using a piece of string, tie one of the pigs ankles.
• Place the pig ventral side up on the dissection tray.
• Bring the string under the dissection tray and tie the opposite wrist.
• Repeat for the other wrist and ankle to expose the ventral surface.

Incisions

• Using either a scalpel or dissection scissors, make incision
• Be careful. Do not cut very deep. It is better to begin with shallow incisions.
• Cut from the umbilical chord to the head
• Using your scalpel, make incisions
• Begin at the umbilical chord and cut toward the posterior end of the fetal pig on either side of the chord.
• Using dissection scissors, make incision across the collar of the pig.
• Find where incision ends along the posterior end of your pig. Using a scalpel, make incision down each hind leg.
• Locate the rib cage of your pig. The final incision will go directly below the ribs. Use dissection scissors to cut along the ribcage.
• Be very careful so you do not damage any of the internal organs.

Exposing the Internal Organs

• Begin folding back the flaps of skin at incision
• Pin down the flaps to expose the internal organs.
• Note the layer of connective tissue holding the abdominal organs in place.
• This tissue is called peritoneum.
• Carefully remove the peritoneum to expose the internal organs.
• Fold back the posterior flap made by incisions. Pin it down.

Organ Identification for the Abdominal Cavity

• The liver will be brown or dull red
• It will be found at the anterior end of the abdominal cavity, right below the ribs.
• Look for the gall bladder, it will be right below the liver.
• Find the duct connecting the gall bladder and the gall bladder.
• Identify the portion of the Small Intestines that the duct connects to.
• Next, identify the stomach. The stomach will be partially covered by the liver.
• Locate where the stomach connects to the esophagus.
• Using dissection scissors, cut the esophagus just above the stomach.
• Repeat this for where the stomach joins the duodenum.
• Now, use your dissection scissors to open the stomach.
• Record what you see inside the stomach.
• Our next organ of interest is the pancreas. The pancreas will be found below the stomach.
• It will be resting against the back wall of the abdominal cavity.
• The spleen will be found near the pancreas, along the left abdominal wall.
• Lastly, identify the small and large intestines. Take hold of the duodenum.
• Slowly pull the duodenum. The small intestines are lined in a membrane called the mesentery.
• Continue to pull out the Small Intestine until it is fully unraveled.
• Measure the length of the Small Intestine.

Organ Identification for the Thoracic Cavity

• If you have not already pinned back the thoracic cavity flaps, do so now.
• You may need to use the surgical scissors to cut through the sternum
• Locate the heart. The heart is found just left of the center of the thoracic cavity.
• Use the forceps to remove the pericardium membrane from the heart.
• You will now begin removing the heart
• Use your blunt probe to locate the right atrium.
• Using your scissors, separate the atrium from the superior and inferior vena cavae
• Next, locate the left atrium with your blunt probe.
• Again, use your scissors to separate the heart from any connecting vessels.
• Separate the aorta from the left ventricle.
• Separate the pulmonary trunk from the right ventricle.
• Carefully remove the heart from the thoracic cavity.

Dissection of the Heart

• Make a small incision separating the left and right sides of the heart.
• Make a cut through the wall of one of the ventricles.

The Lungs

• Locate the lungs within the thoracic cavity.
• Run you finger over the trachea and the lungs.

William Anderson (Schoolworkhelper Editorial Team)

William completed his Bachelor of Science and Master of Arts in 2013. He current serves as a lecturer, tutor and freelance writer. In his spare time, he enjoys reading, walking his dog and parasailing. Article last reviewed: 2022 | St. Rosemary Institution © 2010-2024 | Creative Commons 4.0

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