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Tears are produced by the lacrimal gland, situated just outside the eye. Blinking the eyelids distributes the tears to keep the eyes moist, clean and lubricated. Excess tears are drained via the punctum through the tiny channels called canaliculi located on the inner side of the eyes into the tear sac, from there to the tear duct, the nose and finally down the throat.
The lacrimal punctum (pl.: puncta) or lacrimal point is a minute opening on the summits of the lacrimal papillae, seen on the margins of the eyelids at the lateral extremity of the lacrimal lake. There are two lacrimal puncta in the medial (inside) portion of each eyelid. Normally, the puncta dip into the lacrimal lake.
The lacrimal gland is a compound tubuloacinar gland, it is made up of many lobules separated by connective tissue, each lobule contains many acini.The acini composed of large serous cells which, produce a watery serous secretion, serous cells are filled with lightly stained secretory granules and surrounded by well-developed myoepithelial cells and a sparse, vascular stroma.
There is a single lacrimal canaliculus in each eyelid, a superior lacrimal canaliculus in the upper eyelid and an inferior lacrimal canaliculus in the lower eyelid. The canaliculi travel vertically and then turn medially to travel towards the lacrimal sac. At the bend, the canaliculus is dilated and called the ampulla.
Along the inner margin of the tarsus are modified sebaceous glands known as tarsal glands (or meibomian glands), aligned vertically within the tarsi: 30 to 40 glands in the upper lid, and 20 to 30 in the lower lid, which secrete a lipid-rich product which helps keep the lacrimal secretions or tears from evaporating too quickly, thus keeping the ...
right and left varieties exist; large clamp with two limbs; self-retaining with big discoid ends used to hold and prevent an entropion from bleeding during its surgery Nettleship's punctum dilator: to dilate the lacrimal punctum of the lacrimal apparatus of the eye for syringing or operations Cystotome
Canaliculodacryocystostomy is a surgical correction for a congenitally blocked tear duct in which the closed segment is excised and the open end is joined to the lacrimal sac. [8] [10] Canaliculotomy involves slitting of the lacrimal punctum and canaliculus for the relief of epiphora [8] A dacryoadenectomy is the surgical removal of a lacrimal ...
Crossing the lacrimal sac, it divides into two parts, upper and lower, each attached to the medial end of the corresponding tarsus of each eyelid. [2] As the ligament crosses the lacrimal sac, a strong aponeurotic lamina is given off from its posterior surface; this expands over the sac, and is attached to the posterior lacrimal crest.