Fetal Pig Dissection: External Anatomy And Digestive System

Name: ______Score: ______Organ Systems and Organs Exploration Using a Fetal Pig Honors

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 a. involved with making children 1. Nervous System ____

b. system where food is broken 2. Integumentary System ____ down and nutrients are absorbed 3. Respiratory System ____ c. external and internal barrier 4. Digestive System ____ d. excretes (removes) waste from blood stream 5. Excretory System ____

e. fights off disease 6. Skeletal System ____

f. made of a group of organs that 7. Muscular System ____ make chemicals to slowly regulate body 8. Circulatory System ____

g. communication system in the 9. Endocrine System ____ body (relays fast messages) 10.Reproductive System ____ h. helps body move its structure 11.Lymphatic System ____ 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.  Kidneys  Small intestines   Diaphragm  Bladder Colon (large intestines)   Liver  Heart Epiglottis   Gall bladder  Lungs Ureters   Stomach  Trachea Bronchial Tubes  Spleen  Esophagus  Pancreas 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. ______

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. ______

______

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?) ______

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 where do they get their oxygen from while in the womb? Explain. ______

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. ______

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. ______

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.)

______

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. ______