Using an oscillating saw and chisel, divide the first rib close to the manubrium and sternoclavicular joint to remove the manubrium.

Mobilize the clavicles by sharply dissecting their muscular attachments. Loosening the acromioclavicular (AC) joints with a chisel may facilitate this mobilization.

Reflect the clavicles laterally.

Identify the thymic remnant as the retrosternal fat pad and elevate it.

Identify the left subclavian, left internal jugular and left brachiocephalic veins.

Locate the right internal jugular, right subclavian and right brachiocephalic veins and the superior vena cava (SVC).

Question 1: What is the function of the thymus?

Divide the left brachiocephalic vein medially and reflect laterally to expose the subclavian artery.

Note the relationship of the subclavian artery and vein to the first rib and to the anterior scalene muscle (vein anterior, artery posterior, interposed by anterior scalene).

Place one clavicle back in position to gain an appreciation of the thoracic outlet (costoclavicular interval). The right side may have been disturbed from the preservation process.

With the clavicles laterally rotated, find the subclavian vessels and first rib again. Locate the trunks of the brachial plexus.

Note the phrenic nerve on the anterior surface of the anterior scalene muscle.

Remove the costal and vertebral pleura from the superior and medial chest wall to expose the intercostal vessels and nerves. You may need to retract the subclavian artery superiorly.

Identify T1 spinal nerve passing over the first rib to join the C8 spinal nerve.

Identify the intercostal neurovascular bundle along the inferior side of a rib along with its components: vein, artery and nerve.

Find the sympathetic chain and look for lateral branches to the intercostal nerve (rami communicantes) and medial branches to the heart and lung.

Reflect the right and left brachiocephalic veins.

Re-identify the arch of the aorta and locate the origins (root) of the great vessels: brachiocephalic, left common carotid and left subclavian arteries.

Follow the brachiocephalic superiorly and identify its right common carotid and right subclavian branches. Note the subclavian artery is posterior to the anterior scalene. The subclavian artery becomes axillary artery after it passes over the first rib.

Identify the phrenic nerve on the anterior surface of the anterior scalene.

Return to the root of the great vessels. Identify the right common carotid artery and subclavian artery. Note the vagus nerve passes anterior to the subclavian artery.

Retract the ascending aorta to the left to identify trachea and its bifurcation, the carina.

Retract the trachea to the right and identify the esophagus deep to it.

Examine the aortic arch and surrounding structures from the left.

Identify the pulmonary trunk, left pulmonary artery and mainstem bronchus. Identify ligamentum arteriosum, left pulmonary artery and aorta.

Identify the vagus nerve and follow its branching. Note the close relationship between the ligamentum arteriosum and left recurrent laryngeal branch of the vagus.

Also re-identify the phrenic nerve.

View the posterior mediastinum from the right. Identify the thoracic aorta, esophagus and azygos vein.  Locate the thoracic duct posterior to the esophagus and to the right of the aorta.

Remove as much pleura as possible from the vertebral column and chest wall to expose the mediastinum.

Identify an intercostal vein, artery and nerve.

Expose the sympathetic chain. Identify the thoracic splanchnic nerves and rami communicantes.

Examine the superior surface of the diaphragm.

Identify right and left hemidiaphragms. Note the central tendon of diaphragm and the attachment of the pericardium.

Locate the inferior vena caval, esophageal and aortic hiatuses.

Question 2: What are the vertebral levels of these hiatuses?