174 VISCERAL ANATOMY. 



THE PLEURA. 



What are the Pleurae ? Two delicate serous sacs, one surrounding each 

 lung and reflected over the pericardium, the diaphragm, and the inner surface 

 of the thorax. 



Where do the Pleurae meet ? For a short space behind the middle of 

 the sternum, at the approximation of the anterior borders of the lungs. 

 What Names are given to the parts of the Pleurae ? The 

 Pleura Pulmonalis, or Visceral Layer, covers the lung, and invests that 



organ as far as its root. 

 Pleura Costalis, or Parietal Layer, lines the inner surface of the parietes of 



the chest. 

 Cavity of the Pleura, is the space between the two layers. 



What is the Ligamentum Latum Pulmonis ? The Broad Ligament 

 of the Lung is a triangular fold or reflection of pleura, which descends from 

 the root of the lung posteriorly to the upper surface of the diaphragm. 



State the Differences between the Pleurae. The right sac is shorter, 

 wider, and reaches higher into the neck than the left. 



Enumerate the Parts in Relation with the Left Pleura. Its 

 Visceral Layer, is in contact with the left lung. 



Parietal Layer, is in relation with the vertebral column, the ribs, intercostal 

 muscles and vessels, the sternum, the left sympathetic nerve, the diaphragm, 

 the arched portion of the subclavian artery, and the origin of the left carotid, 

 the left pneumogastric, phrenic and cardiac nerves, the trachea, oesophagus, 

 aorta and the pericardium. 



What is the Mediastinum ? It is the space between the two pleurae in 

 the median line of the thorax, extending from the sternum to the vertebral 

 column, and containing all the thoracic viscera except the lungs. 



Enumerate the Contents of each of its Divisions. The 

 Anterior Mediastinum, contains the 



Origins of the Sterno-hyoid and Sterno-thyroid Muscles. 

 Triangularis Sterni Muscle. Thymus Gland. 



Left Internal Mammary Vessels. Lymphatics. 



Middle Mediastinum, contains the 



Heart and Pericardium. Bifurcation of the Trachea. 



Ascending Aorta. Pulmonary Arteries and Veins. 



Superior Vena Cava. Phrenic Nerves. 



Posterior Mediastinum, contains the 



Descending Aorta. Pneumogastric Nerves. 



Azygos Veins. Splanchnic Nerves. 



Superior Intercostal Veins. Thoracic Duct. 



CEsophagus. Lymphatic Glands, 



