下壁 - Paries inferior
The floor is directed upward and lateralward, and is of less extent than the roof; it is formed chiefly by the orbital surface of the maxilla; in front and laterally, by the orbital process of the zygomatic bone, and behind and medially, to a small extent, by the orbital process of the palatine. At its medial angle is the upper opening of the nasolacrimal canal, immediately to the lateral side of which is a depression for the origin of the Obliquus oculi inferior. On its lateral part is the suture between the maxilla and zygomatic bone, and at its posterior part that between the maxilla and the orbital process of the palatine. Running forward near the middle of the floor is the infraorbital groove, ending in front in the infraorbital canal and transmitting the infraorbital nerve and vessels.
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
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