Fetal Pig Dissection!
• Work in Groups of 3-4
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 –
– SAVE Outer bag
– Cut open the inside bag over the sink. Empty
pig and contents into sink. THROW AWAY
the INSIDE bag into the GREEN trash
• Rinse off pig well. Towel dry and place in
a dissection tray
External Observations
• Look for the umbilical
cord
External nares
– Try to find the
umbilical arteries/veins
that connected its
blood supply to mom
via the placenta
• External nares
(remember what
those are?)
• Tongue
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
midsaggital 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 (see
page 409 of lab
book)
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 – 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
• Using a combination
of scalpel and
scissors:
Heart
– Cut off the
pericardial sac
Superior Vena
that surrounds the Cava
heart
– Be careful not to cut
off any important
blood vessels!
• 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
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
(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 – 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
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
heart
Spleen
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!