What is the cephalic portion of the sympathetic system?

What it is

• The cephalic portion of the sympathetic system begins as the internal carotid nerve, which appears to be a direct prolongation of the superior cervical ganglion. It is soft in texture, and of a reddish color. It ascends by the side of the internal carotid artery, and, entering the carotid canal in the temporal bone, divides into two branches, which lie one on the lateral and the other on the medial side of that vessel.
• The lateral branch, the larger of the two, distributes filaments to the internal carotid artery, and forms the internal carotid plexus. The medial branch also distributes filaments to the internal carotid artery, and, continuing onward, forms the cavernous plexus.