Heart Dissection Lab
Purpose of this lab:
To review the structural characteristics of the human heart and to examine the major features
of a mammalian heart.
Procedure
1.
Obtain a preserved heart. Rinse it with water thoroughly to remove as much of the
preservative/blood as possible. Also run water into the larger blood vessels to force any blood
clots out of the heart chambers. You can even try to fill the heart with water and squeeze the
ventricles and watch the water squirt out of the veins/arteries like it would during a
contraction.
2.
Place the heart in a dissecting tray with its anterior surface up:
a. Locate the pericardium, which appears as a thin layer of tissue
on the surface of the heart. Use a scalpel to remove a portion of this layer
and expose the myocardium beneath. Also note the abundance of fat along
the paths of various coronary arteries. This adipose tissue occurs in the loose
connective tissue that underlies the pericardium.
b. Identify the following and show them to Mr. Tackmann.
Right atrium
Right ventricle
Left atrium
Left ventricle
Superior Vena Cava
Pulmonary Artery
Pulmonary Arteries
Coronary arteries
Aorta
Pulmonary Vein
c. Take a picture of the heart (anterior view). You will need to label the above features
later in this picture
3.
Examine the posterior surface of the heart. Locate the stumps of superior and inferior
vena cava that enter the right atrium. Demonstrate this connection by passing a slender probe
through them (pencil/pen/finger).
4.
Open the right side of the heart. To do this, follow these steps:
a. Insert a blade of the scissors into the superior vena cava and cut downward
through the atrial wall. The arrow in the picture shows where this cut will roughly
be starting.
b. Open the right atrium and locate the tricuspid valve and examine its cusps.
5.
Continue your cut down the right side of the heart all the way down to the apex of the
heart.
a. Continue cutting downward through the tricuspid valve and the right
ventricular wall until you reach the apex of the heart.
b. From the apex cut up through the left ventricle through the left atrium towards the
top of the heart.
c. You’re working your way towards cutting the heart in to perfect anterior and posterior
halves. In other words you are making a frontal plane cut on the heart.
d. Once you finish your cut remove the anterior side of the heart and you should have two
perfect halves that look like the picture below.
6.
a. Locate the following and show them
Inside of Right Atrium
Inside of Right Ventricle
Endocardium
Tricuspid Valve
Mitral Valve
Heart Strings
to Mr. Tackmann
Inside of the Left Atrium
Inside of the Left Ventricle
Interventricular Septum
Pulmonary Valve (this one is HARD to find)
Aortic Valve (step 7 helps you find this one)
b. Take a picture of the heart (interior view). You will need to label the above features
later in this picture
7.
Locate the aorta, which leads away from the left ventricle, and proceed as follows:
a. Compare the thickness of the aortic wall with that of the pulmonary trunk.
b. Use scissors to cut along the length of the aorta to expose the aortic valve
at its base.
c. Examine the cusps of the valve and try locate the openings of the coronary
arteries just distal to them.
8.
One last thing. Starting in the Right Atrium, call Mr. Tackmann over and walk him through
all 14 steps to blood flow on your heart.
9.
Play around with your heart at your set now if you’d like. See if you can removing
different valves in one piece as if you were a cardiac surgeon. When you’re all done you can
dispose of your heart in the garbage and clean up your area.
10.
Get the conclusion sheet in the front of the room and complete your lab report.