Fig. 121. Transverse Section through the Trunk, at the level of 

 the 1st and 2nd Dorsal Vertebra. 



Frozen Section. The section passes through the 2nd Dorsal Vertebra anil the Disc between the 1st and 



2nd Dorsal Vertebrae, also through the ist and 2nd Ribs, through the lower part of the Trachea, 



Thyreoid Gland and Clavicle ; the shoulder-joint on either side and Scapula with their muscles have been 



cut through. The shoulders ii*erc rather elevated. 



The important details are: — 



1 ) Apices of Pleurae as seen from below are unequal because the section is not 

 absolutely horizontal (Difference ' /,„th inch). The Apices of the Lungs separated by 

 the section have been removed. The Subclavian Artery on the left side arching 

 over the Apex of the Lung, and its intimate relation to the 1st rib and the Scalene 

 Muscles is noticed. 



2) Course of the Trachea and Oesophagus; the former deviates a little to the right 

 probably' owing to the asymmetry of the Thj'reoid Gland whereas the Oesophagus 

 normallj' deviates to the left. 



3) When the Thyreoid Gland is much enlarged (as in the inhabitants of the Saxony 

 Mountain Districts) it not only surrounds the Trachea, but also touches the Oeso- 

 phagus and exerts pressure on the Carotid Artery and thin-walled Jugular Vein — 

 both vessels being pushed backwards and outwards. 



4) The Brachial Plexus, on either side, has been cut through. 



51 The Vagus Nerve is situated between the Carotid and Jugular Vessels (cf. Figs. 59, 

 61, and 113). Recurrent Laryngeal Nerve between the Trachea and Oesophagus 

 (cf. Figs. 69 and 113). 

 The space between the Vertebral Column and the front of the neck is remarkably 

 small for the passage of the important Cervical Structures. 



Finally, the Tendon of the Long Head of the Biceps is seen in its groove and the 

 subscapular bursa between the Subscapularis Muscle and the scapular or shoulder-joint is shewn. 



Fig. 122. Transverse Section through the Thorax, at the level of 



gth Dorsal Vertebra. 



Frozen Section. The sectio7i is made through the gth Dorsal Vertebra, the 4th to f}th ribs ; in front the 



Stermtin is divided jitst below the articitlation of the 5th rib. As the man had died from Pneitmonia the 



lungs are fully expanded and not in the cadaveric expiratory position. 



This figure shews clearly how the Thorax is occupied b\' the 3 cavities (Pericardium con- 

 taining the Heart, Pleurae containing the Lungs) and the spaces or Mediastina (cf. Fig. 112, Text). 



The Anterior Mediastinum presents a verj* small space occupied by loose connective- 

 tissue, fat and lymphatic glands, and shews that the pericardium is not completely covered 

 by Pleura. 



In the Posterior Mediastinum at some distance to the left of the Vertebral Column 

 the descending Aorta is seen, on the right side the Oesophagus with both Vagus Nerves, 

 whereas between the Great and Small Azygos Veins the Thoracic Duct is cut across, posteri- 

 orly is the sympathetic cord, and behind the right Vagus nerve is a small lymphatic gland. 



This figure instinctively shews the position of the Phrenic Nerves between the Peri- 

 cardium and Parietal Pleurae which is a point of considerable practical importance in Pleurisy. 



On either side at the 7th rib in the Axillar\- line the Interlobar Pulmonary fissure 

 is seen. 



