The lacrimal apparatus refers to the structures involved in the production, secretion, and drainage of tears. It consists of several components, including:
1. Lacrimal Gland: This gland is located in the upper outer corner of each eye and is responsible for producing tears. It secretes tears onto the surface of the eye through small ducts.
2. Lacrimal Ducts: These are small channels that carry tears from the lacrimal gland to the surface of the eye. There are several ducts that distribute tears across the conjunctiva, the clear membrane covering the front of the eye.
3. Conjunctival Sac: This is a space between the eyelids and the eyeball where tears collect. It helps to keep the eye moist and lubricated.
4. Lacrimal Canaliculi: These are tiny channels that collect tears from the conjunctival sac. There are two canaliculi in each eye, an upper and a lower one.
5. Lacrimal Sac: This is a small pouch located at the inner corner of the eye. It collects tears from the canaliculi and serves as a reservoir for tears before they are drained.
6. Nasolacrimal Duct: This is a narrow tube that connects the lacrimal sac to the nasal cavity. It allows tears to be drained from the eye into the nose, which is why we sometimes experience a runny nose when crying.
Overall, the lacrimal apparatus plays a crucial role in maintaining the health and lubrication of the eyes by producing and draining tears.