Fetal Pig Dissection! Work in Groups of 3-4

External Observations 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 External nares Tongue

External Observations Scrotum 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 midsagittal incision from chin to umbilical cord 2. Then use scissors to cut along either side of the umbilical cord to create a “flap”

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

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 Diaphragm Diaphragm

Separate Skin from rib cage & neck Using your scapel – separate the skin of the chest area off of the rib cage. Also skin the neck area. 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

Exposing Larynx and Trachea – pg. 409 Using a SHARP scalpel – remove all muscle and tissue overlying the larynx and trachea Trachea Larynx

Neck Blood Vessels 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. Heart Superior Vena Cava Right Lung Left Lung

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

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 (end of colon) Beginning of Rectum

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

Fetal Pig Dissection – Day 2

Cardiovascular System 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

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 or URINARY BLADDER Rectum Left Kidney Right Kidney Left Ureter Right Ureter Allantoic or Urinary Bladder

Reproductive System - MALE Allantoic or Urinary 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