Anamtomy And physiclogy Labs 1,3,and 4

EXPERIMENT 8: SKELETAL SYSTEM OF THE FETAL PIG In this experiment, you will become familiar with the skeletal system of the fetal pig. Because the fetal pig did not reach full gestation, many of the bones are not completely developed. Rather, they are cartilaginous. Nevertheless, we can look at these structures to gain a better understanding of the joints and the axial and appendicular skeleton.

PROCEDURE 1. To begin, lay down your underpad and place your dissecting tray on top of it. Be sure you have all of your safety equipment

on before beginning.

2. Once prepared, gently open the bag your pig is in.

Note: DO NOT destroy this bag or empty out the preserving solution within the bag. You will need it for the whole semester.

3. Lay your pig onto the dissecting tray, dorsal side facing up. Slide the strings over the dissection tray to hold the pig in place.

4. Observe Figure 22, which illustrates the skeletal system of a grown pig. Notice the similarities and differences between the human and pig skeleton. 1 – 3

Experiment 8Skeletal System of the Fetal Pig Materials Fetal Pig

Dissection Tray

String (attached to pig’s hooves)

Dissection Tools Kit

Experiment Inventory

Figure 22: The pig skeleton.

5. Due to the rigidity of your pig, it typically will not stay in the dorsal position on its own. As a result, you will need to hold it while you are examining its skeletal system.

6. Begin by examining the axial skeleton through the skin, as shown in Figure 23. Feel the bones of the skull, the continue down the vertebral column, feeling the vertebrae along the way. Notice that the tail of the pig is composed of caudal vertebrae. Note your observations in Table 31.

7. Slide the strings off of the dissection tray, and gently turn your pig ventral side up. Slide the strings back under the dissection tray when the pig is correctly positioned (Figure 23).

8. Feel the thoracic cage of the pig. Though you will not cut into the pig today, feel the similarities between the fetal pig and the human skeleton model. Note your observations in Table 31.

9. Next, observe the appendicular skeleton. The pig’s four appendages correlate to human arms and legs. Use Figure 22 as a guide to try and feel the different bones of the arms and legs (humerus, femur, tibia, etc.). Note your observations in Table 31.

10. In Figure 22, look at the pelvic girdle of the pig. This structure appears noticeably different than that of a human. However, the innominate bones of the pig are created by the ilium, ischium, and pubis.

11. Now, focus on the joints of the pig. The pig may be rigid due to the preservation fluid. However, you should still attempt to produce the movements created by synovial joints (e.g. flexion, rotation). Notice the joints at which these movements are possible. Do they correlate to human movement? Note your observations in Table 31.

12. You are now finished with the external observations of the pig skeletal system. Remember that, as you dissect your pig, you will be able to touch and feel the bones of the skeletal system. As the dissection progresses, always take note of the bones present.

13. To finish, locate the bag the pig came in. Gently place the pig back into the bag, and tightly secure the bag with a rubber band, or place the pig in the zip-seal bag provided in the dissection box.

14. Place the pig back into the cool environment you had previously stored it in. Remember, the best place to keep the pig is in a cool, dark place.

15. After your pig has been put away, clean off your dissecting tray with soap and water. There should not be any biological scraps because you did not cut into the pig. However, biological scraps should not be thrown into the garbage.

16. Clean the area in which you worked with soap and water. As long as the underpad has not been damaged, keep it for future experiments.

Figure 23: Palpate the skeleton of the fetal pig using gloved hands.

Data Sheet Experiment 8 Data Sheet Table 31: Skeletal Region Observation

Skeletal Region Observations

Axial Skeleton

Appendicular Skeleton

Joints