Download PRE-LAB Questions

Name: ______McClanahan______________________________
Class: __Key______
Fetal Pig Dissection
MATERIALS (per group)
latex free gloves
goggles
lab aprons
dissecting pan (1)
dissecting scissors (1)
dissecting probe (1)
forceps (1)
dissecting pins (6)
fetal pig specimen
PRE-LAB Questions
https://www.whitman.edu/academics/departments-and-programs/biology/virtual-pig
Anatomical References
The following terminology will be used to identify the location of body parts throughout the dissection.
anterior – towards the head
ventral – towards the belly
posterior – towards the tail
proximal – lying near the point of reference
dorsal – towards the backbone
distal – lying further from the point of reference
Using the virtual dissection, label the above terms on the three different pigs below.
Anterior
Dorsal
Posterior
Ventral
V
Proximal
Distal
Sexing Your Pig/ External Anatomy
1. How can you tell the gender of a fetal pig?
Urogenital Papilla (Opening) is in different spots.
2. Where is this structure located on the fetal pig?
- Male papilla is just posterior to the umbilical cord
- Female papilla is in front of the anus
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3. What is the function of the skin?
Protection, temperature regulation, as well as the external receptors to environmental stimuli.
Digestive System Questions
1. Write the name of each structure through which food travels in the digestive system (in the correct
order). Mouth, esophagus, stomach, small intestine, large intestine, rectum, anus.
2. What are the structures that aid in digestion but food does not travel through?
Liver, gallbladder, pancreas
3. What is the function of the tongue?
Contributes to chewing, swallowing, and sensing food.
4. What is mechanical digestion? Where does it take place?
Mechanical digestion is physical digestion or chewing of food. This takes place in the mouth and
stomach.
5. What is chemical digestion? Where does it take place?
Chemical digestion is the use of enzymes like those found in saliva and the stomach to break down
food. Mouth and stomach.
6. Where does most of the digestion of food occur?
Stomach
7. Where does absorption of nutrients from the food occur?
Small Intestine
8. What organ houses large amounts of symbiotic bacteria?
Large Intestine
9. What is the function of the liver?
Production of bile, which helps carry away waste & breakdown fats in the small intestine; production
of proteins for blood plasma; production of cholesterol to help carry fats through the body; glucose
to glycogen to help regulate blood sugar levels; processes blood that leaves stomach & intestines &
breaks down nutrients; produces urea for the production of urine.
10. What is the function of the pancreas?
Produces the hormone insulin which promotes sugar uptake from blood.
Excretory System Questions
1. What is urine?
a watery, typically yellowish fluid stored in the bladder and discharged through the urethra. It is one
of the body's chief means of eliminating excess water and salt and also contains nitrogen
compounds such as urea and other waste substances removed from the blood by the kidneys.
2. What is the function of the kidneys?
To separate urea, salts & toxins from the blood.
Circulatory System Questions
1. What four major things does the circulatory system transport?
Oxygen, CO2, nutrients & hormones (chemical messengers)
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2. Why is a four-chambered heart the most efficient?
Separates the oxygenated and un-oxygenated blood.
Reproductive System Questions
1. What is the function of the testes?
Produce sperm & testosterone
2. What is the function of the ovaries?
Produce eggs & estrogen
3. Other than gametes, what else do the ovaries and testes produce?
Hormones
4. What other body system would ovaries and testes function in based on the answer to question 3.
Endocrine System
Respiratory System Questions
1. What gas is inhaled into the lungs?
Oxygen
2. What gas is exhaled out of the lungs?
Carbon dioxide
3. What is the function of the diaphragm? How does it work?
The function of the diaphragm is to aid in respiration. As the diaphragm moves down, the lungs can
take in air. When the diaphragm moves up, it pushes CO2 out of the lungs.
4. Explain how the circulatory and respiratory systems are interdependent upon each other.
The respiratory system exchanges gases with the circulatory systems and the circulatory system
transports those gases.
Nervous System Questions
1. What is the function of the spinal cord?
The spinal cord carries out two main functions: It receives information from the external or
peripheral nervous system and sends those impulses (messages) to the brain; transmits signals
from the central nervous system (brain) to the rest of the body.
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LAB DISSECTION PROCEDURES – make sure a lab apron and goggles are worn the entire time
External Anatomy
1. Place the pig on its side in the tray as shown in figure 1.
2. Use figure 1 to locate the following external structures on your pig: thorax, abdomen, umbilical
cord, external nares (nostrils)
Head
Region
Neck
Thorax
Region
Abdomen
Tail
Region
Figure 1.
Color Key
teats
Digestive = brown
Circulatory = red
Reproductive = blue
Respiratory = green
Excretory = yellow
Nervous = orange
Skeletal = purple
Integumentary = pink
Immune = black
umbilical
cord
3. Place the pig in the tray ventral side up as shown in figure 2.
4. Use figure 2 to locate the following structures on your pig: nipples (teats), urogenital opening, and
scrotal sac (males only).
Based on external features, what is the gender of your pig? _________________________
Figure 2.
Female
Male
Color Key
Digestive = brown
Circulatory = red
Reproductive = blue
Respiratory = green
Excretory = yellow
Nervous = orange
Skeletal = purple
Integumentary = pink
Immune = black
teats (nipples)
umbilical cord
urogenital opening
urogenital papilla
scrotal sac
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Internal Anatomy – Digestive System
1. Place the pig in the dissecting tray ventral side up. Pry open the mouth using a dissecting probe.
2. Using scissors, cut through the joint between the upper and lower jaws to aid in observations.
3. Find the tongue and notice the taste buds on the tongue. Does your pig have teeth? _________
4. Using figure 4, locate the pharynx, the mouth cavity that begins at the jaw hinges and extends to
the esophagus.
5. Locate the esophagus in the back of the pharynx.
6. Use dissecting pins to pin each of the limbs of the pig down to the tray.
7. Use dissecting scissors to make the initial incisions as directed by figure 3. You can avoid cutting
into the underlying organs by pulling up the umbilical cord with the forceps as you cut. It is better to
carefully cut twice rather than damage the organs beneath the muscles with one deep cut.
Caution: The initial cut may cause preservative to spurt or splash out.
8. Use dissecting pins to pin open the abdominal cavity of the pig flat on the tray.
9. If you have excess fluid in the abdominal cavity, rinse your pig at the sink.
10. Using figure 4, locate the liver. Notice that the umbilical vein runs from the liver to the umbilical
cord. You will need to cut the umbilical vein to pin down the area that contains the umbilical cord.
11. You will need to remove the liver in order to see many of the digestive organs. Ask your teacher for
help if you are having problems removing the liver.
12. Using figure 4, identify the following structures of the digestive system on your pig: esophagus,
stomach, small intestine, large intestine, rectum, liver, gall bladder, and pancreas. (Note: the gall
bladder is the pouch located beneath the liver; the pancreas is the cottage cheese-looking structure
beneath the stomach)
13. Using your forceps or dissecting probe, separate the folds of the small intestine and notice the
mesentery that holds it together.
Figure 3.
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Figure 4.
tongue
opening to pharynx
taste buds
larynx
esophagus
thymus gland
trachea
right atrium
left atrium
lung
rib cage
coronary artery
right ventricle
left ventricle
coronary artery
diaphragm
liver
stomach
spleen
pancreas
small intestine
large intestine
caecum
mesentary
urinary bladder
umbilical artery
umbilical vein
region of
anus
rectum
Color Key
Digestive = brown
Circulatory = red
Reproductive = blue
Respiratory = green
Excretory = yellow
Nervous = orange
Skeletal = purple
Integumentary = pink
Immune = black
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Internal Anatomy – Circulatory & Respiratory Systems
1. To identify structures of the circulatory and respiratory systems, you will need to open the chest
(thoracic) cavity. Use dissecting scissors to carefully cut through the ribs and sternum. Using
dissecting pins, pin open the thoracic cavity of the pig.
2. Remove the thymus gland so that the chambers of the heart will be accessible.
3. Using figure 4, identify the following structures of the circulatory system on your pig: right atrium, right
ventricle, left atrium, and left ventricle
(note: if your pig has been injected with latex dyes, the arteries will be red and the veins will be blue)
4. Using figure 4, identify the following structures of the respiratory system on your pig: trachea, lungs,
and diaphragm
Internal Anatomy – Excretory & Reproductive System
1. To identify structures of the excretory and reproductive systems, you will need to open the lower
abdominal cavity. Use dissecting scissors to carefully cut the lower abdominal cavity. Using dissecting
pins, pin open the lower abdominal cavity of the pig.
2. Using figure 5, identify the following structures of the excretory system on your pig: kidney, ureter,
urinary bladder (remember that the urinary bladder is located within the umbilical cord)
3. Using figure 5, identify the following structures of the reproductive system on your pig: ovaries, fallopian
tubes, uterus (if female). If you have a male pig, open the scrotal sac to locate the testes.
Figure 5.
Color Key
Digestive = brown
Circulatory = red
Reproductive = blue
Respiratory = green
Excretory = yellow
Nervous = orange
Skeletal = purple
Integumentary = pink
Immune = black
kidney
ureter
ovary
fallopian tube
uterus
urinary
bladder
ovary
testes
urethra
scrotal
sac
Clean up:
 Remove the pins from your pig
 Dispose of your pig and all organs/tissues in the appropriate trash bag.
 Wash (with soap!) and dry the dissecting area, tray, and dissecting instruments.
 Throw away gloves & paper towels in the appropriate trash bag.
 Thoroughly wash your hands.
 Return goggles and lab apron.
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