a) (i) Name the cavity of the body in which the heart and lungs are located - Leaving Cert Biology - Question 7 - 2009

One significant way that heart muscle differs from other muscles in the body is that it does not tire due to its involuntary nature.

1. Positioning: Start by ensuring that the heart is positioned ventral side up, allowing clear access to all surfaces.
2. Initial Cut: Make an incision on the anterior side of the heart to open the right atrium. This allows for immediate visibility of the atrial structures.
3. Further Dissection: Using scissors, cut towards the base of the heart (the aorta area) to display the ventricles. Ensure to identify the left and right structures as you dissect.
4. Safety Precautions: Always use scissors carefully and maintain focus on the structures being cut to avoid injury.
5. Labelling: Identify and label major components like the right atrium, tricuspid valve, and right ventricle on the diagram.

To expose a semi-lunar valve, I cut open the aorta or the pulmonary artery to reveal the location of the valves clearly.

In my diagram of the dissection, I have drawn the right atrium at the top, leading into the tricuspid valve, which then connects to the right ventricle. Each structure is clearly labelled to indicate their respective locations.