they are a by-product of the pork food industry Why

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Pre-AP BiologyIntro to the Fetal Pig Dissection
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Why Fetal Pigs

• 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

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Why cont.

• 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

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Advantages to Dissection

• 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.

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Safety

• 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.

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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.

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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).

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IMPORTANT

• 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?

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Dissection Basics

• 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

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Anterior Posterior
Dorsal Ventral
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Viewing the Pig

• 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

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Determine the sex of your pig

• 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.

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Female Male
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Responsibility

• 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
• Lets begin dissecting your fetal pig

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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 teachers tutorials.

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For the Overview Quiz Next Time

• 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.