Download - Fetal Pig Dissection!
Fetal Pig Dissection!
• Work in Groups of 3-4• Get out lab books and lab packets!
Fetal Pig Dissection – Day 1Getting Started!
Obtain the following materials:1 fetal pig per group
1 large dissection pan2 pieces of string - ~25-30 inches long
2 good scalpelsScissors
2 BLUNT ProbesForceps (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• 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!
Scrotum
Anus
Genital Papilla
Anus
BOY!
GIRL!!!
Securing your Pig to the tray
• Use the 2 pieces of string to secure your pig to the dissecting tray
Incision Time1. 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 Time3. & 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
Internal Jugular Vein
Common Carotid Artery
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 LungLeft Lung
Cardiovascular System:Superior Vena Cava, Pulmonary Trunk & Aortic Arch
Superior Vena Cava
Right Lung Left Lung
Aortic ArchPulmonary Trunk
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
Liver
Gallbladder
Small intestine
Large intestine
Mesentery
Rectum
Note: the following are not shown, but you need to know where they are:Tongue, esophagus, stomach, pancreas
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
Right Kidney
Left Kidney
Right UreterLeft Ureter
Allantoic Bladder
Rectum
Reproductive System - MALE
Allantoic Bladder
testes
Penis
Spermatic Cord
EpididymisEpididymis
Spermatic Cord
testes
Reproductive System - FEMALE
Allantoic Bladder
Ovary
Ovary
Uterine Horn
Uterine Horn
Uterine Body
Cardiovascular System – Heart & Spleen
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
Internal Jugular Vein
Common Carotid Artery
External Jugular Vein
Cardiovascular System:Superior Vena Cava, Pulmonary Trunk & Aortic Arch
Superior Vena Cava
Right Lung Left Lung
Aortic ArchPulmonary Trunk
Cardiovascular System:Inferior Vena Cava & Abdominal Aorta
Inferior Vena Cava
Small Intestine
Mesentery
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!