The lacrimal gland is located in the lacrimal fossa of the extraorbital frontal bone, about 20mm long and about 12mm wide. It is fixed on the orbital periosteum by connective tissue, and the lateral aponeurosis of levator palpebrae superioris passes through it, which divides the lacrimal gland into larger orbital lacrimal gland and smaller eyelid lacrimal gland. Under normal circumstances, the lacrimal gland can't be touched in the eyelid. Levator palpebrae superioris, Lockwood ligament and inferior supporting ligament play an important role in lacrimal gland fixation. If the tension of the ligament or levator palpebrae superioris muscle is weakened, lacrimal gland prolapse will occur clinically.
The upper part of lacrimal gland clings to orbital periosteum, the rear part is connected with orbital fat, the lower part is adjacent to eyeball, and the inner end rests on levator palpebrae superioris muscle. At the same time, the gland leaves of lacrimal gland itself are dense and fragile, so lacrimal gland tumors are easy to involve orbital periosteum and surrounding tissues, and it is easy to recur after operation. The blood supply of lacrimal gland comes from the branch of lacrimal artery of ophthalmic artery and enters in the center of posterior lacrimal gland.
Blood reflux enters the superior ophthalmic vein through the lacrimal vein and finally flows into the cavernous sinus. There are three nerve components in the lacrimal gland. Sensory nerve comes from the eye branch of trigeminal nerve, which forms a neural network in lacrimal gland secretory cells to supply glands, branches outside the excretory duct, and finally supplies the lateral conjunctiva and eyelid skin through glands.
A considerable number of cases of cylindrical adenocarcinoma of lacrimal gland show the symptoms of sensory nerve invasion at the initial stage of the disease, and the clinical exophthalmos is not obvious, but the pain and headache on the affected side have become important complaints, which are caused by the infiltration of cancer cells around the sensory nerve, which is very helpful for diagnosis and differential diagnosis. Sympathetic nerve fibers from internal carotid artery plexus and parasympathetic nerve fibers of facial nerve control lacrimal gland secretion.
Sympathetic nerve controls normal lacrimal gland secretion, and parasympathetic nerve controls a large amount of tear secretion. If the lacrimal gland is removed, as long as the accessory lacrimal gland and goblet cells are not destroyed, conjunctival dryness may not necessarily occur clinically.