BIO 139 Virtual Lab 2
The Pig Heart
The vessels and structures of the Pig Heart
Note: Since pigs walk on all fours, technically the views of the heart should be "ventral" and "dorsal" rather than "anterior" and "posterior" but the human terminology is used here to facilitate comparisons with the human heart model and diagrams.
This page created and maintained by Udo M. Savalli. Last updated August 13, 2005.
- Identification Hints:
- The first step is to determine the orientation of the heart. Note that the large cut that opens the heart is somewhat to the right of mid-sagittal on the anterior surface of the heart. Also note that the aorta opens towards the posterior.
- Ventricles: The left ventricle is much thicker-walled than the right ventricle (why the difference?) and dominates the posterior and inferior portions of the heart. The right ventricle is more anterior-superior. Since the main cut in the hearts is anterior, both ventricles are cut open.
- Aorta: the most conspicuous vessel on the heart, and unlikely to be collapsed. Its opening faces posteriorly (or superiorly if cut before the arch). You may also notice openings in its superior surface, which represent the brachiocephalic and subclavian arteries. Following the aorta back into the heart takes one to the left ventricle, through the aortic semilunar valves.
- Pulmonary Trunk: a large vessel that extends up from the right ventricle and then posterio-laterally across the superior surface of the heart. Depending on how the specimen was cut, it may have an apparent opening or may branch into the pulmonary arteries. From the interior, one can identify the pulmonary trunk by passing a probe through the pulmonary semilunar valve (right ventricle).
- Vena Cava: the vena cavas are large (but collapsed) veins on the right-posterior side of the heart. The superior vena cava points more superior-anteriorly and is relatively easy to identify as there are no other large vessels nearby. The inferior vena cava points inferior-posteriorly, and its cut end is usually near the pulmonary veins. It can be distinguished by passing a probe from the superior through to the inverior vena cava.
- Pulmonary Veins: several collapsed veins that open on the posterior side of the heart. They connect to the left atrium (use fingers or a probe to trace where they go). They, like the vena cavas, can sometimes be hard to see unless held open by a probe or pin.