Name __________________________
Pd. _______
Pig Heart Dissection Laboratory Handout
Background: Mammalian hearts are quite similar in that they are all four-chambered. The adult pig
heart is approximately the size of an adult human’s fist. The structure and size was so similar to that of a human’s that they were once
used in human heart transplants, but this practice has since been discontinued.
In this activity, students will become more familiar with the anatomical structures of the human heart by dissecting, studying, and
identifying the parts of a pig heart. The primary focus is on the anatomy and flow of blood through the heart.
Materials:
Textbook or resource materials with labeled pictures or diagrams of the mammalian heart
Gloves
One per pair or triple: Preserved pig heart Dissecting tray Scalpel Scissors Probe
External Anatomy:
Procedure:
1. Surrounding the heart is a tough layer of connective and epithelial tissue called the pericardium. The sac-like structure of the
pericardium is often removed earlier, during the heart’s removal from the chest cavity. Try to find any remaining parts of the
pericardium around the top of the heart.
First and foremost find the anterior side of the heart. Look for the pulmonary trunk. It will lie across the anterior side of
the heart. Place a probe into the pulmonary trunk. What chamber does it connect to? Determine the anterior side and call Ms.
Beatty over for confirmation.
2. Identify the atria. The right atrium will be on the left and posterior and the left atrium will be on the right and in anterior. The
atria are also removed by accident in most cases. The atria have very little muscle tissue because they do not pump blood very
far. If there is any atrial tissue remaining, it is easily recognized as flap-like muscle at the top of the heart. On the inside, it
appears to have numerous pockets into which blood may settle.
3. Identify the ventricles. The left ventricle is the more muscular of the two ventricles because it must generate enough force to
pump blood throughout the entire body. The right ventricle pumps blood to the lungs, which are nearby. Therefore, the right
ventricle has less muscle tissue. Locate the left and right ventricles.
4. Look for the coronary arteries, especially the anterior interventricular artery (L.A.D.). Remember, you are responsible for
identification of the coronary arteries and cardiac veins. I may ask you about them on the models or on the pig hearts. You
may not see the actual vessel on the pig heart but you should know where they are located.
The coronary arteries branch off the aorta and run along the outer surface of the heart on the dorsal and ventral sides. These
vessels generally run along the location of the sulci, which are found, between the ventricles.
5. Locate the aorta. Place a probe into the aorta. What chamber does it connect to?
**Many of the large arteries and veins are cut close to the heart itself when it is removed from the animal. However, the origin of the arteries is within the heart
itself and along with the semilunar valves can be observed when you inspect the heart internally.
Internal Anatomy:
Procedure:
Once you have determined the anterior sign of the heart and identified external structures, you are now ready to make your cut.
Locate the apex of the heart. Using a scalpel (BE VERY CAREFUL, THE SCALPELS ARE SHARP) make an incision
from the apex up through the ventricles, through the atria and through the major vessels. Cut carefully, but deeply as the heart
will be very tough.
RIGHT SIDE:
Observe:
Locate the superior and inferior vena cava to find the right atrium.
Locate the coronary sinus and the superior and inferior vena cava. (Sometimes it is easier to find the opening to these
vessels from the inside of the right atrium)
Notice the thickness and texture of the walls of the right ventricle. Which is thicker, right or left? Why?
Locate the tricuspid valve
Locate the chordae tendineae
Locate the papillary muscles
Locate the pulmonary arteries (Most have been cut off. Check the model to view.)
Locate the cusps of the pulmonary semilunar valve (you must cut back through the pulmonary trunk to see these at the base)
LEFT SIDE:
Observe:
Locate the aorta. probe inside the aorta and explore the semilunar valve.
Locate the aortic semilunar valve.
Locate the openings to the coronary arteries at the inferior end of the aorta.
Notice the thickness and texture of the walls of the left ventricle. Which is thicker, right or left?
Locate the bicuspid valve or Mitral valve
Locate the chordae tendineae
Locate the papillary muscle
MODELS:
Observe:
ligamentum arteriosum
coronary arteries
cardiac veins
Clean-Up:
1. Wash dissecting tools and trays thoroughly, dry them with a paper towel, and return to proper set-up location.
2. Clean up all organic material from your desk, floor, sink and surrounding area and throw it in the trash.
3. Wash all table tops with 409. Please dry the sinks and table tops.
Pig Heart Dissection Lab Name___________________________
Anatomy & Physiology Period #_____
Label the diagram of the human heart below.
1___________________________________
2. __________________________________
3. __________________________________
4. __________________________________
5. __________________________________
6. __________________________________
7. __________________________________
8. __________________________________
9. __________________________________
10. _________________________________
Analysis Questions
1. How can you tell which side of the heart is the ventral surface?
2. How many chambers are found in the mammalian heart? List these chambers.
3. Which chambers are the pumping chambers of the heart?
4. Which chambers are the receiving chambers of the heart?
5. Compare the structure of the tricuspid valve with that of the pulmonary semilunar valve.
6. How do the walls of the atria compare with the walls of the ventricles and why are they different?
7. What is the purpose of heart valves?
8. Name & compare the heart valves found between the upper & lower chambers of the right and left
sides of the heart.
9. Vessels that carry blood away from the heart are called __________, while __________ carry blood
toward the heart.
10. Which artery is the largest and why?
11. What is the purpose of the coronary artery and what results if there is blockage in this vessel?
12. Can an artery carry deoxygenated blood? Explain.
13. Using words, trace blood flow through the major blood vessels and heart, starting with deoxygenated blood
returned from the body. Attach another page if necessary.
