The shiny membrane lining the thoracic cavity and covering the surface of the diaphragm is the parietal pleura. The pleural layers from each side meet along the midventral line forming the mediastinum, which divides the thoracic cavity into two halves.
The heart lies within the mediastinum and is suspended in the pericardial sac, which is formed from parietal pericardium. Note the layers of yellow fat lying on the surface of the pericardial sac.
The shiny membrane covering the surface of the lung is the visceral pleura.
Click here to view the circulation about the heart.