tarsus

The tarsi (: tarsus) or tarsal plates are two comparatively thick, elongated plates of dense connective tissue, about in length for the upper eyelid and 5 mm for the lower eyelid; one is found in each eyelid, and contributes to its form and support. They are located directly above the lid margins. The tarsus has a lower and upper part making up the palpebrae. Superior The superior tarsus (tarsus superior; superior tarsal plate), the larger, is of a semilunar form, about in breadth at the center, and gradually narrowing toward its extremities. It is adjoined by the superior tarsal muscle. To the anterior surface of this plate the aponeurosis of the levator palpebrae superioris is attached. Inferior The inferior tarsus (tarsus inferior; inferior tarsal plate) is smaller, is thin, is elliptical in form, and has a vertical diameter of about . The free or ciliary margins of these plates are thick and straight.