Fetal Pig Lab Word File SP20 PDF

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Fetal Pig Lab with labeled photos and answers...

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Kingdom Animalia V: Mammalian Anatomy of the Fetal Pig NAME_________________________________________ During this lab you will observe the external and internal anatomy of the fetal pig. Follow the detailed instructions included in the pages of this lab exercise. In addition, during the dissection refer frequently to: The Virtual Pig Dissection at https://www.whitman.edu/academics/departments-andprograms/biology/virtual-pig to verify structures and quiz yourself Perry and Morton’s Photo Atlas for Biology pgs. 115-119. NOTE error on pg. 116: what is labeled as small intestine is actually large intestine; what is labeled as large intestine is actually small intestine. STRUCTURES TO KNOW FOR THE PRACTICAL EXAM: mouth lungs tongue nipples anus urogenital opening umbilical cord hard palate soft palate epiglottis external ears pancreas external nares thoracic cavity abdominal cavity diaphragm liver gall bladder spleen esophagus kidneys ureters urinary bladder coelom trachea thymus thyroid larynx stomach (including cardiac & pyloric ends with sphincters) small intestine (including the duodenum and cecum) large intestine and rectum heart (including, pericardium, pulmonary trunk, aortic arch, coronary artery, right atrium, left atrium, right ventricle, left ventricle) abdominal aorta (dorsal body wall filled with pink latex) inferior vena cava (dorsal body wall filled with blue latex) parietal peritoneum – the slick membrane lining the body cavity visceral peritoneum – the slick membrane covering each of the organs mesentery – double layer of membrane connecting organs to each other & body wall (see small intestine) In males: penis, epididymis, spermatic cord, testes, scrotum, In females: genital papilla, ovaries, oviducts, uterine body, uterine horns (KNOW BOTH SEXES) Fetal Pig Dissection Instructions External anatomy: Locate the following structures: mouth, anus, nipples, nares, external ears, umbilical cord, front limbs and hind limbs. Identify anterior, posterior, dorsal and ventral Sex your pig (determine if female or male); use photo atlas and online photos. Locate urogenital opening. Determine if scrotum or genital papilla are present. Tell your instructor the sex before proceeding. Using string “hog-tie” the pig in the dissecting pan ventral surface up: Tie string around one front leg, under tray, up and tie around other front leg. Repeat with hind legs. Legs should not move when tied correctly. Identify structures in oral cavity by making deep cuts in the corner of each jaw (can be 2–3 inches long. You may have to cut through bone). Find hard palate, soft palate, tongue, teeth etc. and push down on base of tongue to find small white crescent shaped epiglottis.

Incisions: make ventral incisions according to diagram in order 1, 2, 3…etc. Start with a scalpel through skin and muscle until body cavity exposed. Then proceed with scissors always pointing up and away from you. Start incision 1 above the umbilicus and proceed anteriorly staying very shallow in the neck region (above the arrow point in the diagram) and stopping when you reach the hairs on chin. Incision 2 is an upside down U due to the penis in male pigs being located under the skin posterior to umbilicus. You must all make this incision in this way! After incision 2 cut the umbilical vein to pull back that flap To start incision 3 feel with fingers for the bottom of the rib cage and proceed laterally on both sides. To open the thoracic cavity more you will have to cut through ribs where they attach to breast bone. Locate the diaphragm, the flat thick membrane below the lungs that is attached to the body wall. You can also cut the diaphragm where it attaches to the body wall proceeding with scissors from ventral to dorsal. Then leave the diaphragm intact. The region of the coelom (ventral body cavity) above the diaphragm is the thoracic cavity. Below the diaphragm is the abdominopelvic cavity of which the abdominal region is anterior to the pelvic region. Incision 4 will make abdominal organs more visible. Ventral Incisions of Fetal Pig:

Dissecting throat region: Be careful! Make a very shallow scalpel cut through the skin and deepen cut with needle like probe. Use a probe to separate tissues; find the larynx, or voice box a large round hollow white structure. Posterior to that air leaves the larynx and enters the trachea, or wind pipe, a long white hollow tube. Run the side of a probe down the trachea to feel the cartilaginous rings which keep this airway open. Using a blunt probe carefully push the trachea towards the pigs right and locate the esophagus a thinner collapsible tube dorsal to the trachea. Ventral to the trachea locate the thyroid gland, a roundish organ, tapered at either end. Thymus gland is located on either side of the trachea and sometimes can be embedded in the tissue lateral to the trachea. Open body flaps and proceed to identify major organs listed in your lab manual (and on which you’ll be quizzed): the large liver just below the diaphragm, the gall bladder, a small sac embedded in the undersurface of the right lobe of the liver, the spleen, a long thin flat organ where red blood cells are stored and the right and left lungs in the thoracic cavity on either side of the heart. Identify the thick tough pericardium surrounding the heart. Carefully tear the

pericardium and push it to the side to better see the surface of the heart. Identify the pulmonary trunk the most anterior of the large vessels and posterior to that locate the region of the aortic arch. If your pigs were injected with latex, the arteries will contain pink latex and veins will contain blue latex. Identify the coronary artery on the anterior surface of the heart, and the regions of the right atrium, left atrium, right ventricle and left ventricle. Gently lift the liver to find the sac like stomach which is usually flattened and empty. Identify the anterior cardiac region of the stomach (closest to the heart) & the pyloric region where it joins the small intestine. With a gloved hand feel the pyloric sphincter where the stomach joins the small intestine. This regulates passage of stomach contents into the stomach. Identify the first region of the small intestine the duodenum a short curved region. Within the mesentery of the duodenum and below the stomach is the long thin pancreas. Follow the small intestine to where it joins the large intestine. Where the two meet identify the blind sac called the cecum. Although pigs don’t have an appendix this is where your appendix is located. Unlike yours the large intestine in pigs is tightly coiled. Finally, locate the short straight rectum, the tube through which feces leave the body. Finally locate the spleen, a long thin flat organ where red blood cells can be stored. Identify the parietal peritoneum lining the body cavity, the visceral peritoneum covering the organs and regions of mesentery. The best place for seeing mesentery is the small intestines. Many blood vessels will be visible between the two layers of peritoneum that make up the mesentery. Kidneys and ureters are on the back wall and are retroperitoneal (behind the peritoneum) so you will have to gently lift and push the intestines to the side to locate them. The kidneys are fairly large. Find a kidney and then use a needle like probe to tear through parietal peritoneum to uncover it. Then locate the ureter, a tube that carries urine from the kidney where it’s produced to the urinary bladder where it’s stored. The urinary bladder in these fetal pigs is located on the inner surface of the umbilical flap Gently push the small intestines to the side and locate the abdominal region of the inferior vena cava and abdominal aorta. These will be on the back wall in the region of the rectum. The aorta will be a long tube with a thick whitish wall. If you make a tiny scalpel cut in the wall it should be filled with pink latex. Nearby will be the thinner walled collapsible vena cava containing blue latex. Reproductive system Female reproductive structures are deep in pelvic cavity. You will not need to make any incisions to observe them. Locate the two tiny bean shaped ovaries. On their upper surface will be the oviducts, tiny coiled tubes. The uterus in pigs is bifurcate or horned. Locate the two uterine horns. Press down on the posterior part of the horns to see where these join into the body of the uterus Male reproductive anatomy can be observed after completing the following dissection: Scrotum, spermatic cord, testes, epididymis

Palpate the scrotum to feel if the two testes are present (in very young fetus’s they may not yet have descended from the abdominal cavity through the inguinal canal). If you cannot find them ask for help from your instructor. Make an incision through the wall of the scrotum with a scalpel just to the side of the midline of the scrotum. (the incision should go anterior to posterior, not laterally) Reach into the upper region of the incision with a gloved finger and pull out the large white fibrous spermatic cord. The spermatic cord will contain blood vessels, nerves, the vas deferens, testes and epididymis. You need to uncover the testes and epididymis. Feel for the hard oval testes about halfway up the spermatic cord and make an incision to one side away from the testes. Then tease this open with a dissecting needle and pull the testes out. On one side of the testes you will see the C shaped coiled epididymis. Urogenital Opening and Penis Just posterior to the umbilicus is the urogenital opening (or orifice of the penis). The penis is under the skin directly posterior to the opening. The original incisions opening the body cavity should have been made with an upside down U shape and the umbilical vein cut so that there is a flap containing the umbilicus and the 4-5 cm below it. Palpate this flap in the region below the urogenital opening to feel for the long narrow cylindrical penis. Use a scalpel to make a midline incision (anterior to posterior) to one side of the penis. Then use a dissecting needle to tease out the penis from the surrounding tissue. Remember to observe the other sex pig’s reproductive system before leaving! You are responsible for knowing both! IMPORTANT NOTES: Make sure scissors are always pointing up so as not to destroy underlying tissue. Be especially carefully in the neck region; do not make deep incisions or you may destroy underlying structures or cut trachea. Remember: the scalpel is only used for initial incisions! Then you can expose structures using the point of a dissecting needle. Do not remove any structures from your pig! Your pig practical exam will be on the pigs dissected in this class so structures must remain intact and in the correct location. Consider photographing your dissected pig. This way you can study from your photos as well as your photo atlas and the Virtual Pig site. CLEAN UP Make sure you observe a dissected pig of the opposite sex before leaving since you are responsible for knowing the structures on both sexes. In addition, before putting your pig away ask if there are any students who still need to observe the opposite sex so you can teach them the structures on your pig. At the end of this lab spray the open body cavity of the pig with wetting solution (if available), close the ventral body flaps and place wet paper towels over the area of the incisions and open throat region. Do not remove the strings on the limbs. Put your pig in a Ziploc bag. Label the bag with your initials and “McManus” and leave it on the cart provided. As always, wash and dry all of your dissection tools and return them to the tray. Disinfect your lab bench and wash your hands.

FETAL PIG LAB PRACTICAL You will not have an oral quiz on the pig dissection today. Instead, on the last lab session of the semester you will have a 30 point lab practical that you will complete independently and that uses all of the pigs dissected in your lab section. You will be responsible for the structures listed in both male and female pigs and a word bank will be provided. Pins with numbers from 1 – 30 will be placed in specific structures in the pigs and they will be placed around the room. There may also be cards next to some pigs with specific questions. Students will stand in a line and rotate through the pigs, spending 1-2 minutes at each pig, with only one student at a pig at any one time. When everyone has rotated through all of the pigs students can return to a pig a second time.

10 point LAB ASSIGNMENT: Answer the questions about the anatomy of the fetal pig on the remaining pages. You may need to look ahead in your textbook since all organ systems may not have been covered in lecture at this time. Submit this before entering the lab for the pig practical. PGM 8/6/19 MAMMALIAN ANATOMY: The external and internal anatomy of the fetal pig NAME___________________________ QUESTIONS (10 pts) Answer these questions and submit them for grading the day of the Fetal Pig Practical. 1. State the names of the following taxa to which the pig belongs. Anamalia, Chordata, Mammalia, Artiodactyla, Suidae, "Sus scrofa"

Domain: _Eurkarya___________________________________ Supergroup:_________________________________ Kingdom: animalia___________________________________ Phylum: ___chordata_________________________________ Vertebrate Clade: suidae_____________________________ 2. After examining the external structure of the fetal pig list the 3 features you observe externally on the pig that identify it as a mammal. ____________________________________________ hai randf ur ,mammar ygl ands,si ngl ebondedl owerj aws

______

__________________________________________________ __________________________________________________ 3. What was the sex of the fetal pig you dissected?_________________ Before dissecting the pig, the presence or absence of what external structure(s) allowed you to make this determination? female: genital papilla directly under tail and anus, urogenital opening is in between the genital papilla and anus male: scrotum under tail and anus, penis under the skin, urogenital opening is directly under umbilical cord ________________________________________________________ Male: Longer than female. Urogenital opening just posterior to umbilical cord Female: Shorter than male. Urogenital opening immediately ventral to tail and anus ________________________________________________________ Thesexofpi gwasdet er mi nedbyur ogent i al openi ng. Onf emal esi twasl ocat edneart heanus. On mal esi twasl ocat edneart he umbl i cal cor dandf emal epi gsur ogent i alpai l l ai sl ocat edneart hegent i alopeni n Mal eUr ogeni t al openi ngi sneart heumbi l i cal cor d. Theyl ackur ogeni t al papi l l a Femal eur ogeni t alpapi l l ai spr esentneart hegeni t al openi ng. ur ogeni t alopeni ngi sl ocat edneart heanus.

4. Nipples are the external openings of the mammary glands. Which sex(s) of the pig has nipples? ____ bot hmal eandf emal epi gshav eni ppl esl i kehumans .

______________________________________ 5. What is the function of the umbilical cord? Umbi l i cal cor di st opr ovi denut r i t i ont ot hef et us . .I tc onnect st hef et ust ot heut er usoft hemot her

It serves as the connection between the fetus and placenta. The vessels withing the cord are responsible for nutrient, gas, and waste between the fetus and the mother The cord that supplies the fetus with nutrients and other resources while in the mother's uterus. It attaches at the placenta and helps to bring/take oxygenated and deoxygenated blood to/from the fetus. supplies fetus with nutrients and other resources while in the uterus; attaches to the placenta

____________________________________________________________ 6. After making the abdominal incisions and opening the body cavity you should have located the diaphragm. The diaphragm separates what two body cavities? separates thoracic cavity from the abdominal cavity ________________________________________________ 7. List the major organs found in the thoracic cavity: hear tl ungsandt hymusgl ands

________________________________________________________ ________________________________________________________ 8. List the organs of the abdominal region of the abdominopelvic cavity: l i v ergal l bl aderspl eenhear tki dney s

________________________________________________________ ________________________________________________________ ________________________________________________________ 9. List the organs of the pelvic region of the abdominopelvic cavity: s t omach,ur i nar ybl adder, hear t

______________________________________________________________________________ __________________________________ 10. Referring to your lecture notes or textbook, list in order the names of the structures through which the air passes on its way from the pharynx to the alveoli of the lungs: On its way to the alveoli of the lungs air travels through the nasal cavity, pharynx, larynx, trachea, bronchi and bronchioles. nostrils --> Pharynx --> Larynx --> Trachea --> Bronchi --> Bronchioles --> Alveoli

11. Referring to your lecture notes or textbook, list in order the names of the structures in the gastrointestinal tract through which food/chyme/feces passes on its way from the pharynx to the outside of the body: Mouth --> Pharynx --> Esophagus --> Stomach --> Small Intestine --> Large Intestine --> Anus 1. mouth 2. pharynx 3. esophagus 4. cardiac sphincter 5. stomach 6. pyloric sphincter 7. duodenum 8. small intestine

9. large intestine 10. colon 11. rectum

12. For each of the following accessory organs of the digestive system list the molecules they secrete into the gastrointestinal tract. - Amylase: Break down starches - Chyme: Responsible for the final stages of enzymatic digestion - Cellulase: Breaks down cellulose which allows the animal's own digestive enzymes to access the proteins and carbohydrates within the plant cell E. The Pancreas - accessory organ of digestion 1. Function a. production and secretion of digestive enzymes (proteases, carbohydrases or amylases, and lipases) b. production and secretion of sodium bicarbonate - necessary to neutralize the chyme once it leaves the stomach and enters the small intestine c. the pancreas is an exocrine (digestive enzymes and bicarb) and an endocrine (insulin and glucagon) organ 2. Anatomy a. the pancreas lies posterior to the stomach and is retroperitoneal b. consists of three areas i. head ii. body iii. tail c. pancreatic duct - leaves the pancreas and empties in the duodenum

F. The Liver - accessory organ of digestion 1. Function - 3 general categories a. metabolic regulation - regulates the composition of circulating blood - removes and stores excess nutrients and corrects nutrient deficiencies by mobilizing stored reserves or synthesizing what is needed b. hematologic regulation - largest blood reservoir in the body; as blood passes through the liver phagocytes remove foreign material; plasma proteins are synthesized; circulating hormones are removed; antibodies are removed; toxins are removed, rendered harmless or stored c. bile production - bile is synthesized and secreted; bile acts as an emulsifier - it breaks

large fat droplets into smaller fat droplets thereby increasing the surface area for lipases to act on - bile is not an enzyme 2. Anatomy of the Liver - the largest visceral organ a. hepatocytes - liver cells b. four lobes - left lobe, right lobe, caudate lobe and quadrate lobe c. covered by a tough fibrous capsule d. falciform ligament - divides the right and left lobes and connects the liver to the anterior abdominal wall e. the hepatic portal system - the nutrient rich venous blood leaving the digestive tract is carried to the liver for processing prior to being dumped into the general venous circulation - the veins that carry this nutrient rich blood make up the hepatic portal system; once the blood has been processed, it is returned to the general venous circulation by way of the hepatic vein f. portal hypertension - if the blood vessels of the hepatic portal system become blocked the pressure in the portal system will rise causing portal hypertension - the ...