Lab 4

Superior Mediastinum

1) Fig 3.163) The thymus (C 112, 113) is likely to be a fatty remnant that lies immediately posterior to the manubrium. (Note: it may be difficult to recognize the thymus in the cadaver)5) Left brachiocephalic vein - Fig 3.27, C 135 6) Right brachiocephalic vein - Fig 3.27, C 1357) C 1268) Azygos vein C 158, 159. Arch of azygos vein passes superior to the root of the

right lung and drains into the posterior surface of the of the superior vena cava (there’s a clear diagram of this on pg. 189 of Gray’s anatomy)

10) Right phrenic nerve and left phrenic nerve C 134, 135 (Note that the right and left phrenic nerves pass anterior to the roots of the right and left lungs, respectively) Demonstrate that the phrenic nerves accompany the pericardiaphrenic vessels and that they enter the superior surface of the diaphram (not so great diagrams demonstrating this on pages 189-190 in Gray’s anatomy) 11) Arch of aorta – Fig 3.27, C 15812) Brachiocephalic trunk, left common carotid artery, and the left subclavian artery - C 155.213) Ligamentum arteriosum (fibrous cord that commects the concavity of the arch of the aorta to the left pulmonary artery) Fig 3.28, C 13514) Left vagus nerve and left recurrent laryngeal nerve Fig 3.29, C 158 (Note: the left vagus nerve passes posterior to the root of the left lung toward the esophagus. Good diagram in Gray’s Anatomy pg. 190). Review the relationship of the left recurrent laryngeal nerve to the ligamentum arteriosum (according to Gray’s, it should be lateral – you kinda see it in C 135). 15) Right vagus nerve and right recurrent laryngeal nerve (loops around the right subclavian artery) Fig 3.29, C 15816) Trachea and tracheobronchial lymph nodes C 156.2 17) Left and right main bronchus (Note that the arch of azygos vein passes superior to the right main bronchus and the arch of the aorta passes superior to the left main bronchus - Fig 3.29)19) Esophogus C 155.2 and C 156.2 20) Carina Fig 3.2921) Right main bronchus larger, shorter, more vertical than left main bronchus

Posterior Mediastinum

1) Fig 3.162) Fig 3.19, C 1353) Note that the esophagus lies immediately posterior to the left atrium and part of

the left ventricle

4) Fig 3.30 (Oblique cardial sinus – C 135)5) C 1586) Esophogeal plexus of nerves Fig 3.30, C 6367) Right vagus nerve C 1628) Left vagus nerve C 1629) Anterior vagal trunk and posterior vagal trunk Fig 3.31 (The vagal trunks

found on the inferior part of the esophagus, just before it passes through the diaphragm; passes with the esophagus

10) C 15911) Fig 3.31, C 15912) Hemizygos vein and accessory hemizygos vein C 15913) Thoracic duct C 158 (retract esophagus to the left and look for thoracic duct

between the azygos vein and the thoracic aorta; thoracic duct is immediately to the left of the azygos vein and posterior to the esophagus; it has appearance of a small vein without the blood in it)

14) C 159 (Gray’s anatomy pg. 198)15) C 15916) Thoracic aorta C 15817) Esophogeal arteries and bronchial arteries C 15818) Posterior intercostal arteries C 15919) Intercostal nerve C 15920) Sympathetic trunk C 16221) C 16222) Rami communicantes C 16223) Greater splanchnic nerve C 162 (Note that the greater splanchnic nerve receives

contributions from the 5th to 9th thoracic sympathetic ganglia and that it is not completely formed until lower thoracic levels. Greater splanchnic nerve found on sides of vertebral bodies T5 to T9, whereas the sympathetic trunk crosses the heads of ribs 5 to 9)