Biology:
Intro to the Fetal Pig Dissection
Why Fetal Pigs
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The fetal pig is a mammal, like humans.
Nearly all major structures are the same or similar in
anatomy
While there are some interesting differences between
pigs and humans, the most important things are very
similar.
Fetal pigs are not bred for the purpose of dissection,
they are a by-product of the pork food industry
Why cont.
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Fetal pigs are not killed for the purpose of dissection
Those that are not used for education will be used for
fertilizer production or discarded
Most people do not think of pigs as 'pets'
Fetal pigs are relatively inexpensive. Even in the extra
large size, where structures are well developed, they
can be obtained for about 1/3 the cost of a similarly
sized cat
Advantages to Dissection
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Dissection is a hands-on, investigatory kind of activity
for students. Dissection allows students to "test the
truthfulness" of what they see in books.
Dissection impresses on students the normal
variation that is present in the natural world. No two
fetal pigs, even though they are perfectly normal, will
look exactly the same.
In fact, to do well on practical, students MUST looks
at several examples of each structure in different
animals. Occasionally, quite significant anatomical
variations will be noticed.
Safety
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All dissecting tools should be considered
dangerous.
Notify your teacher immediately if you are cut.
Handle probes, dissection scissors, and scalpels
with extreme caution. Always cut away from
you, never toward yourself or another person.
Dissection specimens should be properly
mounted in the dissection pan before cutting.
Safety
5. Do not place your hands near your mouth or
eyes while handling preserved specimens. Most of
the preservatives in use today are non-toxic to the
skin, they may cause minor skin irritations. If the
preservative gets on your skin, wash with soap and
warm water.
6. The preservative should never come in contact
with your eyes because you will have on goggles.
If you remove your goggles and it does, you must
wash your eyes (holding them open with hands) in
an eyewash or in the sink for 15 minutes.
Safety
7. Inform your teacher BEFORE the lab starts
next time if you have any allergy to latex. (This
should already be noted on your safety contract)
The class will then use vinyl gloves.
8. Wear lab gloves, APRONS, and goggles at all
times.
9. Lab gloves and paper towels go in the regular
trash. Skin and pieces of pig go into the
separate plastic bag provided by your teacher
(not down the sink).
IMPORTANT:
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Do not rinse off your pig in the sink as
you will wash off the chemical that keeps
it preserved. What do you think would
result?
Dissection Basics
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dorsal: toward the back of the body
ventral: toward the underside of the body
anterior (cranial): toward the head end of the
body
posterior (caudal): toward the tail end of the
body
Anterior
Dorsal
Ventral
Posterior
Viewing the Pig
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Note the thin peeling layer of tissue covering
the body of your pig.
This layer is the epitrichium, a layer of
embryonic skin that peels off as hair develops
beneath it.
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Identify the regions of the body:
head (cranial) region, neck (cervical)
region,trunk region (thoracic region), tail
(caudal) region
Determine the sex of your pig:
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Female: Look for a single urogenital opening
just ventral to the anus. A prominent genital
papilla projects from the urogenital opening.
Male: Look for the scrotum, a sac-like
swelling containing the testes and located
ventral to the anus. The male urogenital
opening is faintly visible just posterior to the
umbilicus. Note that males as well as
females have multiple nipples = teats =
mammary papillae.
Female
Male
Responsibility
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It is your responsibility to respect your pig.
It had life and now has the purpose of teaching you
mammalian anatomy
If you choose to disrespect the pig (if you have to ask,
then it is probably disrespect), you also choose to go
out side, dig a grave and give the pig a proper burial.
You will also choose to be written up and be punished
by the principal…
Let’s begin dissecting your fetal pig
What to do if you are absent for a
dissection day…
On your return day, you should ask your lab group to
review with you the structures they were assigned to
observe that day.
 Then, you should visit the following website:
The Virtual Pig Dissection Homepage at
http://www.whitman.edu/biology/vpd/main.html
 This website is a great resource for absent students.
Additionally, it is a great study resource when you are
studying for your practical.
 You can also attend your teacher’s tutorials.
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For the Overview Quiz Next Time…
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Study these notes well!
Also, study the Body Systems Homework
Sheet (front and back) well!
Expect to see a matching of body systems
similar to your Body Systems Homework
Sheet.