It comprises the principal functions of sensation from the maxilla, nasal cavity, sinuses, the palate and subsequently that of the mid-face,[1] and is intermediate, both in position and size, between the ophthalmic nerve and the mandibular nerve.

[2] It begins at the middle of the trigeminal ganglion as a flattened plexiform band then it passes through the lateral wall of the cavernous sinus.

It leaves the skull through the foramen rotundum, where it becomes more cylindrical in form, and firmer in texture.

It then emerges on the face through the infraorbital foramen and terminates by dividing into inferior palpebral, lateral nasal and superior labial branches.

This article incorporates text in the public domain from page 889 of the 20th edition of Gray's Anatomy (1918)