Fetal Pig Dissection! Work in Groups of 3-4 Get out lab books and lab packets!

Fetal Pig Dissection – Day 1 Getting Started! Obtain the following materials: 1 fetal pig per group 1 large dissection pan 2 pieces of string - ~25-30 inches long 2 good scalpels Scissors 2 BLUNT Probes Forceps (tweezers)

Initial Prep Open up the plastic bag – KEEP the outer bag AND the rubber band! Cut open the inner bag over the sink. Empty pig and contents into sink. THROW AWAY inner bag into the GREEN trash Rinse off pig well. Towel dry and place in a dissection tray

External Observations Scrotum Look for the umbilical cord Try to find the umbilical arteries/veins that connected its blood supply to mom via the placenta External nares (remember what those are?) Tongue Boy or Girl? Look under the tail. If all you see it an anus (hole) then a SMOOTH swollen sac of skin – you have found the SCROTUM and you have a boy! If you see an anus (hole) plus an obvious folded area of skin. You have found the GENITAL PAPILLA and you have girl! BOY! Anus Genital Papilla Anus GIRL!!!

Securing your Pig to the tray Use the 2 pieces of string to secure your pig to the dissecting tray

Incision Time 1. Take a scalpel – make a SUPERFICIAL midsaggital incision from chin to umbilical cord 2. Then use scissors to cut along either side of the umbilical cord to create a “flap” 3. & 4. Use scissors to make 2 lateral cuts. Avoid the staples on one side of the pig Also be careful not to demolish the DIAPHRAGM at the base of the rib cage!

Incision Time 3. & 4. Use scissors to make 2 lateral cuts. Avoid the staples on one side of the pig Also be careful not to demolish the DIAPHRAGM at the base of the rib cage! Diaphragm

Separate Skin from rib cage Using your scapel – separate the skin of the chest area off of the rib cage. You will have to cut through muscle and connective tissue to do this It’s like skinning raw chicken! Using scissors – cut of each half of the rib cage. You should end up with 2 large chunks of ribs in your tray

Diaphragm Use scissors to separate the diaphragm from the floor of the rib cage. You should be left with one big “flap” of Diaphragm that hangs over the liver and stomach (see d page 409 of lab book) Diaphragm Diaphragm

Exposing Larynx and Trachea – pg. 409 Using scissors – cut off any remaining pericardial sac that might be covering the heart. Place any pieces in your tray for later disposal Using a SHARP scalpel – remove all muscle and tissue overlying the larynx and trachea Larynx Trachea

Neck Blood Vessels – pg. 418 Using a BLUNT PROBE – carefully probe on either side of the trachea until you expose 1 PINK common carotid artery on each side 2 BLUE jugular veins on each side These are the internal and external jugular veins Common Carotid Artery Internal Jugular Vein External Jugular Vein

Heart Using a combination of scalpel and scissors: Cut off the pericardial sac that surrounds the heart Be careful not to cut off any important blood vessels! Also not the texture and position of the RIGHT AND LEFT LUNGS. Superior Vena Cava Right Lung Left Lung

Cardiovascular System: Superior Vena Cava, Pulmonary Trunk & Aortic Arch Right Lung Left Lung

What now? Locate all Respiratory & Digestive System organs listed on Page 13 of your lab packet! Use pg. 404 & pg. 409 in your lab books for help Note: do NOT find the urinary organs yet – we will do this later. When your group thinks it has found everything – call me over so I can review it with you!

Ready to clean up? Cut off strings – throw away in GREEN trash. Throw any PIG TISSUE WASTE in the RED trash Rinse pig under water and clean both external and internal areas. Spray pig with cavicide (in white spray bottle) inside and out! Put pig in your saved plastic bag and secure with rubber band. Write the pig’s name (or group name) on the bag in permanent marker. Place bagged pig in the tray. Spray down your table with cavicide or simple green!

Respiratory System Make sure you can locate: External nares Larynx Trachea Diaphragm lungs

Digestive System Be sure you can locate: Tongue Esophagus Stomach Liver Gallbladder Small intestine Large Intestine Pancreas Mesentery Rectum

Digestive System Note: the following are not shown, but you need to know where they are: Tongue, esophagus, stomach, pancreas Liver Large intestine Gallbladder Mesentery Small intestine Rectum

Fetal Pig Dissection – Day 2

Urinary System Do NOT cut out the intestines to dissect the urinary system! Push the intestines to one side and use a scalpel or blunt probe to remove the connective tissue around each kidney and ureter Note the ALLANTOIC BLADDER Rectum Left Kidney Right Kidney Left Ureter Right Ureter Allantoic Bladder

Reproductive System - MALE Allantoic Bladder Spermatic Cord Penis testes Spermatic Cord Epididymis Epididymis testes

Reproductive System - FEMALE Uterine Horn Uterine Horn Ovary Ovary Uterine Body Allantoic Bladder

Cardiovascular System – Heart & Spleen

Cardiovascular System – page 418 1 PINK common carotid artery on each side 2 BLUE jugular veins on each side These are the internal and external jugular veins Common Carotid Artery Internal Jugular Vein External Jugular Vein

Cardiovascular System: Superior Vena Cava, Pulmonary Trunk & Aortic Arch Right Lung Left Lung

Cardiovascular System: Inferior Vena Cava & Abdominal Aorta Mesentery Small Intestine Inferior Vena Cava Abdominal Aorta Rectum

Ready to clean up? Cut off strings – throw away in GREEN trash. Throw any PIG TISSUE WASTE in the RED trash Rinse pig under water and clean both external and internal areas. Spray pig with cavicide (in white spray bottle) inside and out! Put pig in your saved plastic bag and secure with rubber band. Write the pig’s name (or group name) on the bag in permanent marker. Place bagged pig in the tray. Spray down your table with cavicide or simple green!