Download Fetal Pig Dissection: External Anatomy and Digestive System

Name: _______________________
Score: ___________
Organ Systems and Organs Exploration
Using a Fetal Pig Academic
An Avatar is a complex organism that is agile, athletic and often participating in
dangerous activities due to the environment in which they live. As part of your
project you will be required to explain how an Avatar is able to interact and
survive in its environment. To understand this organism’s basic physiology
(function), it is crucial to study its basic anatomy (structure).
All multicellular organisms are made out of many layers. The layers are
represented in the picture below. The important thing to understand is that each
layer is used to build the next layer.
For example: the smallest level, called subatomic particles, are used to build
atoms. Atoms are then used to build molecules, molecules are used to make
macromolecules (aka. Organic molecules), macromolecules are used to make
organelles, organelles are used to make cells, etc…
Smallest level
Largest Level
The fetal pig is an organism whose anatomy is very similar to human beings and
Avatar’s. The fetal pig is comprised of the same 11 organ systems as humans and
Avatar’s. A simple sentence can be used to help you remember the 11 organ
systems. Complete the matching task below.
C
DR
SMILE
RUN
1. Nervous System ____
a. involved with making children
2. Integumentary System ____
3. Respiratory System ____
b. system where food is broken
down and nutrients are
absorbed
4. Digestive System ____
c. external and internal barrier
5. Excretory System ____
d. excretes (removes) waste
from blood stream
6. Skeletal System ____
7. Muscular System ____
8. Circulatory System ____
9. Endocrine System ____
e. fights off disease
f. made of a group of organs
that make chemicals to slowly
regulate body
10.Reproductive System ____
g. communication system in the
body (relays fast messages)
11.Lymphatic System ____
h. helps body move its structure
i. provides structure for the
body
j. brings nutrients, oxygen and
other important chemicals
throughout the body
k. brings oxygen and carbon
dioxide in and out of body
This web address, http://www.youtube.com/user/LakelandBiology, has videos of
the internal dissection of the pig. You may wrap your smart phone in plastic wrap
(saran wrap), and access the site to help you through the dissection, as well as to
help you review for the test.
Purpose: To explore the various organ systems and organs in a fetal pig. While
going through your dissection you will describe and capture pictures of the various
structures you will observe.
Materials: scalpel, scissors, dissecting tray, fetal pig, string, tape, camera, plastic
ruler, pen/pencil and paper, and possibly saran wrap for your smart phone.
Unatekoon mayum matukan, okanalu say yee elieya.
Honalu who Eywa. Sey lay ya toowaywoo.
Okeyan sloonahafeape.
Procedures: Fetal Pig Dissection: External Anatomy
Sexing your pig:
1. Determine the sex of your pig by looking for the opening to the urethra (tube that
releases urine from the body). On females, this opening is located near the anus. On
males, the opening is located near the umbilical cord.
If your pig is female, you should also note that the opening is covered with a flap called
the urigenital papilla, which is present near the genital opening. Males do not have this
papilla.
1. Both males and females have rows of nipples, and the umbilical cord will be present in
both. Locate both of them.
2. What is the sex of the pig? __________________
3. Gestation (development in the womb) for the fetal pig is 112-115 days. The length of the
fetal pig can give you a rough estimate of its age. Some are in MILLIMETERS, and some
are in CENTIMETERS
4. 11 mm - 21 days
17 mm - 35 days
2.8 cm - 49 days
4 cm - 56 days
22 cm - 100 days
30 cm – birth
5. How old is your pig (estimate based on the range)? _______________
**Clean the plastic ruler after you use it to measure the length of the pig.
Opening the pig’s mouth:
1. To open the mouth take your scissors and cut straight back on the corners of the mouth
pushing through the jaw bone. The mouth should hinge back.
a. Open the pigs mouth and locate the hard and soft palate on the roof of the mouth. Can
you feel your own hard and soft palates with your tongue?
2. Continue cutting the sides of the mouth backwards until your incision is underneath the
eye of the pig. The epiglottis, a cone-shaped structure at the back of the mouth should
be exposed.
The epiglottis is a flap of skin that will close the opening to the esophagus (swallowing) or
the trachea (breathing).
Integumentary & Muscular System
1. Using your scissors and your scalpel remove the skin from around the body of the fetal
pig. Examine how the skin is connected to the muscles. Record all observations and take
pictures along the way.
2. Once the skin is removed tweeze through the muscles to visualize how they are organized
and attached to the bones. Record all observations and take pictures along the way.
Fetal Pig Dissection: Internal Anatomy
In this activity, you will explore the internal make up of the fetal pig. Remember, that to
dissect means to "expose to view" - a careful dissection will make it easier for you to find the
organs and structures. Be sure to follow all directions.
The Incision
1. Place your fetal pig in the dissecting pan
belly up.
2. Use string to "hog-tie" your pig so that
the legs are spread eagle and not in your
way.
3. Use scissors to cut through the skin,
muscles and bone according to the
diagram to the right. Do not remove the
umbilical cord.
4. After your cuts are done, now cut
through umbilical cord.
Once the fetal pig’s organs are exposed locate as many organs as you can without removing
them. Once you get to a point where you have identified as many organs as possible,
choose one of the following organ systems to remove; Digestive system or Respiratory
system. Try to remove the organ system intact. You may carefully remove other organs in
order to access the organ system, but take pictures of all organs after removing them. As
you remove organs place them in the dissecting tray. Record all observations and take
pictures along the way. There is a description of what each organ looks like on the
following page. Locate the organ inside the fetal pig, and then put a check in the box to
the right of the organ on the next page.
1. Diaphragm. This muscle divides the thoracic and abdominal
cavity and is located near the ribcage. The diaphragm aids in
breathing.
2. Liver – largest internal organ located across the entire
abdomen; it helps detox the body and creates bile. Bile helps
break down fats.
3. Gall bladder – located underneath the liver and stores bile.
4. Stomach - is responsible for churching and breaking down food.
5. Small Intestines & Large Intestines – located after the
stomach (small then large), assist in digestion.
6. Pancreas – located under the stomach; create insulin, which
helps you take sugar out of blood and into cells.
7. Spleen – flat organ that lies across stomach; helps remove dead
Red Blood Cells from the body.
8. Kidneys – two bean shape organs located underneath the
intestines; filter waste from the blood stream and send it to the
bladder.
10. Heart – located between the two lungs; helps pump blood
throughout the body.
11. Lungs – 2 structures located on the sides of the chest; help
bring in oxygen and remove carbon dioxide from the blood.
11. Urinary Bladder – elongated, flat structure that should be attached to
the underside of the umbilical cord.
Post Lab Questions: After dissecting the fetal pig, answer the following questions below.
Answer in complete sentences using evidence from your observations for full credit.
1. What was the largest internal organ that you observed? _______________________
2. Pigs eat almost any kind of food, including dead insects, worms, trees, bark, garbage and
even other dead pigs. Based on one of the major function of the liver, why would the pig
need such a large liver? Explain.
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3. What color was the spleen (flap-like organ over the stomach)? Based on its function, why
would you expect it to be this color? Explain.
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4. All of the stomachs of the pigs were empty. Why wouldn’t any of them be full? (hint:
where does the fetal pig get its food from?)
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5. Like human fetuses, the lungs of the fetal pig were not fully developed. Why are lungs one
of the last organs to develop in fetuses, and from where do fetal pigs get their
oxygen?_____________________________________________________________
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6. The heart of the fetal pig was very large. In humans, the heart starts beating 22 days
into the 9 month pregnancy. Why does the heart start pumping blood to all the cells so
early in pig/human development? Explain.
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7. If you stretched a pig’s or human’s intestines out from end to end, they could be twenty
or more feet long. Based on their function, why do they need to be so long? Explain.
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8. Anatomy is the study of the structure of organs, while physiology is the study of the
function of organs. Why is it important to study anatomy and physiology together? (Hint:
The Wright brothers invented the first flying planes, and they spent a lot of time
studying the shapes of birds’ wings.)
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9. Relating to question 8, the structure of an organ helps it do its job. Describe ways in which the
human’s and another organism’s (snake, rabbit, etc) anatomy are different, and why the features
you describe help each organism survive in the environment in which it lives.
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