Fig. 13. Drawing of gross specimen of posterior of left globe, showing optic nerve surrounded by short posterior ciliary arteries (SPCAs). Wreath of short posterior ciliary nerves (lighter structures) is prominent superiorly and inferiorly. An occasional SPCA accompanies nerves. Temporal (left of optic nerve) and nasal (right of optic nerve) canals of long posterior arteries and nerves mark the horizontal meridian of the globe. Muscular tendon of inferior oblique muscle (far left) partially covers canal of long temporal posterior ciliary artery and nerve. Emissary canals of the four vortex veins lie in the oblique quadrants. Tendon of superior oblique muscle inserts superiorly, just anterior to superior temporal vortex vein. (Courtesy of Stephen Gordon)