part of part of surrounds multi-tissue structure cranial nerve II orbital region common tendinous ring FMA:49071 UBERON:0014796 ligament of Zinn common annular tendon A ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit. Wikipedia:Annulus_of_Zinn common anular tendon annulus of Zinn anulus tendineus tendon of Zinn common tendinous ring anulus of Zinn anulus tendineus communis annulus tendineus communis anulus tendineus communis