Tips For Using This Lab
The activity as written provides a guided study of the anatomy of the mammalian heart and an opportunity to simulate an important medical procedure by guiding students through a coronary artery bypass surgery. Study of the coronary circulation is extremely important for all students as the morbidity and mortality associated with coronary artery disease remains very high among both men and women in the US today.
An additional activity that can be easily incorporated into the lab is to simulate a balloon angioplasty procedure. To do this all that is needed is a short length of narrow gauge tubing and something to fashion a tiny balloon from. I use PE-tubing and a small piece of latex condom. The tubing can be attached to a small syringe for inflation. The tube is inserted into the ostia of the coronary artery located at the beginning of the aorta and slipped along the artery. Once in place by injecting air into the balloon the students can observe the expansion of the artery.
Part I: The "Tell Tale Heart" is an activity during which students familiarize themselves with the structure of the heart. They locate the atria, ventricles, and major blood vessels. Through “surgical” procedures, students perform coronary bypass surgery and correct patent ductus arteriosus. Human and dog hearts are compared in terms of common structure and defects.
Part II: Heartworm Poster has students research the life cycle, epidemiology, and diagnostic procedures and treatment of dog heartworm. Their work culminates with them presenting the information in the form of a poster. After they have completed their work they are given supplemental information and are asked questions about heartworm disease.
Part III: In Heartworm Microfilariae students examine a stained smear of dog blood containing microfilariae and count living microfilariae in a fresh blood sample.
High School Biology: Regents, General, and Honors.
Part I: “The Tell Tale Heart” - approximately 60 minutes for the procedures.
Part II: “Dog Heartworm Poster” - one period to start work and then a week outside of class as homework should be adequate. After the poster is complete, the additional information and questions can be given as a homework assignment.
Part III: “Heartworm Microfilariae ” - two periods: one for making and staining blood smears containing microfilariae, and one lab for examining and counting living microfilariae.
- one pair of dissecting scissors
- one pair of forceps
- one dissecting pan
- one pair of latex or vinyl gloves/student
- two probes
- 2 straws cut in half
- masking or lab tape to label the straws
- a “needle” and 12 inches of bright thread
- one 16-cm section of narrow rubber tubing (Aquarium tubing will work, so would another soda straw if tubing is not available.)
- a reference chart of the heart (this could be a large poster which clearly illustrates the chambers and major vessels.)
- Dog blood containing heartworm microfilariae
- Stain for blood smears
- Diluent for the blood
Price: No Charge
Thea Martin, BOCES, Ithaca, NY
Mary Colvard, Cobleskill-Richmondville High School Cobleskill, New York
Dr. Marguerite Frongillo, Cornell University, Ithaca, New York