Practical anatomy of the rabbit : an elementary laboratory text book in mammalian anatomy / by B.A. Bensley.

  • Benjamin Arthur Bensley
Date:
1918
Catalogue details

Licence: In copyright

Credit: Practical anatomy of the rabbit : an elementary laboratory text book in mammalian anatomy / by B.A. Bensley. Source: Wellcome Collection.

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    left side crosses the ventral surface of the subclavian artery and the aortic arch, passing then along the pericardium to the diaphragm. That of the right side accompanies the thoracic portion of the inferior caval vein. The nerve controls the respiratory movements of the diaphragm. (f) The sympathetic trunk. At the base of the neck the cervical portion of the sympathetic trunk enters the inferior cervical ganglion (g. cervicale inferius). The latter lies in front of and somewhat dorsal to the subclavian artery. The first thoracic ganglion lies behind the artery and is connected with the inferior cervical by the ansa subclavia, a loop formed by two cords, one of which passes to the dorsal, the other to the ventral side of the subclavian artery. The nerves proceeding from the inferior cervical ganglion enter the cardiac plexus and the sympathetic plexuses of the subclavian and its branches. 3. Dissection of the heart. The character and relations of the enclosing serous sac, the pericardium, should first be noted. Its relation to the heart is similar to that of the peritoneum and pleura investing other visceral organs (p. 99). It comprises a parietal layer, that portion com- monly known as the pericardium, and a visceral layer, the epi- cardium, which forms an immediate investment for the heart substance. The parietal layer forms a loose, capacious sac, the serous membrane being greatly strengthened by the presence of a thin layer of connective tissue which forms an external investment and is usually considered as part of the pericardium. The paired pleural cavities containing the lungs are broadly separated by a longitudinal vertical partition, the mediastinum or mediastinal septum, the space enclosed by the latter being largely occupied by the heart and by the cavity of the pericardium. For a considerable area ventrally the pericardium is loosely applied to the thoracic wall, the intervening space, which is bounded laterally by the membrane lining the pleural cavities, being known as the anterior mediastinum. A corresponding dorsal space lying between the heart and the bodies of the thoracic vertebrae, and also bounded laterally by the pleura, is the posterior mediastinum. It is occupied by several structures, namely, the oesophagus, the thoracic aorta, the bronchi, and the pulmonary bloodvessels. The pericardium should be removed, and the external features of the heart and its great vessels examined as follows:
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