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
BOY!
Anus
• 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!
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
Superior Vena
scissors:
– Cut off the
pericardial sac
that surrounds the
heart
– Be careful not to cut
off any important
blood vessels!
Cava
• Also not the texture
and position of the
RIGHT AND LEFT
LUNGS.
Right Lung
Left Lung
Cardiovascular System:
Superior Vena Cava, Pulmonary Trunk & Aortic Arch
Superior Vena
Cava
Aortic Arch
Pulmonary Trunk
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
Gallbladder
Large intestine
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
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
Superior Vena
Cava
Aortic Arch
Pulmonary Trunk
Right Lung
Left Lung
Cardiovascular System:
Inferior Vena Cava & Abdominal Aorta
Mesentery
Inferior Vena
Cava
Small Intestine
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!