The shanks are two relatively thick elongated plate of dense connective tissue, measuring about 2.5 cm long; There is one on each eyelid , and help define the shape of the eyelid and supports. They define the margins of the eyelid. 1 The tarsus has a bottom and a top forming the lid.
The superior tarsal ( upper tarsus , upper tarsal plate), the largest, has a crescent – shaped, about 10 mm wide at its center, and gradually narrow toward their extremities. It is a neighbor of the upper tarsal muscle.
On the front of this plate is attached the aponeurosis of the levator muscle of the upper eyelid .
The lower tarsus ( lower tarsus ; lower tarsal plate) is smaller, lean, with an elliptical shape, and its vertical diameter is about 5 mm. The free margins of these plates are thick and straight.
Orbital margins are connected to the circumference of the orbit through the orbital septum .
The side angles are attached to the zygomatic bone through the palpebral lateral raphé .
The medial angles of the two plates converge the lacrimal sac , and are fixed to the frontal process of the maxilla by the medial palpebral ligament ).
The subtarsalis sulcus is a groove in the inner face of each eyelid.
Along the inner margin of the tarsus are modified sebaceous glands called tarsal glands (or Meibonian glands), aligned vertically within the tarsus: 30 to 40 glands in the upper eyelid, and 20 to 30 in the lower eyelid, which secrete a Lipid-rich product that helps tear secretions or tears do not evaporate too quickly, and therefore keeping the eye moist. 2
- Back to top↑ „eye, human“. Encyclopædia Britannica . 2008. Encyclopædia Britannica 2006 Ultimate Reference Suite DVD 2008
- Back to top↑ Martini, 2006