4.10.6 Lacrimal apparatus
Here's the orbital margin. Here just below and behind it is the lacrimal gland, which secretes tears. It lies in this hollow in the roof of the orbit, the lacrimal fossa. The many small ducts of the lacrimal gland open into the conjuctival fornix up here.
Tears leave the space in front of the eye through two small openings called puncta: here's the lower punctum. To see the upper one we'll roll the upper lid outwards. Here's the upper punctum.
To see where those lead we'll look at a dissection in which the orbicularis has been removed, and blue material has been injected into the puncta. Here's the upper punctum, here's the lower one.
Leading from them are the canaliculi: here's the upper canaliculus, here's the lower one. The two canaliculi converge behind the medial palpebral ligament, which we'll remove. The canaliculi join together, and enter this reservoir, the lacrimal sac.
The lacrimal sac is surrounded by the fibers of origin of the orbicularis muscle. When we blink, the pressure from these muscle fibers squeezes tears from the lacrimal sac, down into the nasolacrimal duct.