Dissection of the neck and thorax, deep dissection, ribs divided and removed, neck muscles divided and reflected. Heart, lungs, aorta, subclavian and carotid arteries, trachea, thyroid gland, submandibular gland shown. Superior cervical ganglion, vagus nerve (cranial nerve X), phrenic nerve, cervical spinal nerves and brachial plexus shown. Anterior view.