Experiment 5 Introduction to the Fetal Pig The dissection experiments in this lab manual use a fetal pig to examine many anatomical systems Because the pig is a mammal many of its anatomical structures are very similar to those of the human body This renders the fetal pig as a realistic model of the systems within the human body Materials Fetal Pig Dissection Tray Dissection Tools Kit String Procedure 1 To begin lay your underpad down and place your dissecting tray on top of it Lay out your dissecting tools 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 into the dissecting tray ventral side up Tie a piece of string to each of the pig s legs forearm to foreleg hind leg to hind leg and tie together the strings from the forearms and the strings from the hind legs on the underside of the dissecting tray allowing the pig s belly to be exposed 4 Look at the exterior of the pig You may notice a thin peeling layer of embryonic tissue covering your pig This layer is called the epitrichium and sloughs off as the pig develops hair 5 Also spend some time looking at the details of the skin Make observations regarding the look and feel of the skin before any dissection has occurred 6 The pig can be divided into four sections the head the neck the trunk and the tail Beginning with the head region locate the snout nares nostrils pinnae external ears and the upper and lower eyelid Make observations in Table 4 regarding what you notice Also list what type of tissue s you think make up these structures 7 Moving to the neck region notice that there are not any external structures present Do pay attention to the thickness of this region 2013 eScience Labs LLC All Rights Reserved 8 Inferior to the neck is the truck region While making observational notes in Table 4 notice the forelegs and hind legs each attached to a shoulder of the pig On each hoof notice there are only four toes 9 Look for the mammary papillae as well Figure 8 Typically a fetal pig will possess five to seven pairs 10 Also take note of the umbilical cord Figure 8 This cord provides contact between the mother and fetus during gestation 11 Caudal of the umbilical cord is the tail Between the umbilical cord and the tail lies the anus of the pig Also located in this region is the urogenital opening Determine the sex of your pig Male pigs will display a penis and a scrotum a sac of skin ventral to the anus Female pigs display labia small folds on both sides of the urogenital opening that come together to form the genital papilla Record your observations in Table 4 12 As you finish with your external observations remember that throughout the dissection you will encounter many different tissues Many tissues lie superficial to the skin and are therefore not currently visible As the dissection progresses always take note of the tissues present in each experiment 13 To finish slide the strings off the dissection tray Keep the strings tied to the hooves of your pig 14 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 in the zip seal bag provided in the dissection box 15 Now that the bag has been opened the pig must be kept in a dark cool environment 16 After your pig has been put away clean off your dissecting tray and dissection tools with soap and water Because we have not cut into the pig there should not be any biological scraps But always remember biological scraps should not be thrown into the garbage Securely store the biological scraps until the end of the term so they can be properly disposed of at one time 17 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 2013 eScience Labs LLC All Rights Reserved Figure 8 The ventral side of the fetal pig Table 4 External Observation of the Fetal Pig Area Observations Skin The pig is a pale pink color The skin is very thick and tough feeling and has a rough texture with a layer of white hair Head Region The eyes were closed while the tongue was out of the mouth abd appeared to be furry with little cuts along the edges 2013 eScience Labs LLC All Rights Reserved Neck Region There is a few rolls of skin with a thicker version of the white hair that covered the body Trunk Region There are no deformities It has all its legs and all its hooves have the same amount of toes It has a cut down the middle I assume where the blood was drained from the pig There are 14 nipples on the underbelly Tail Region including sex of pig The umbilical cord had a cut leading to the trunk and the sex of this pig is a female 2013 eScience Labs LLC All Rights Reserved