kyynelkanavajärjestelmä

The kyynelkanavajärjestelmä, or lacrimal drainage system, is a biological system responsible for the drainage of tears from the eyes. This system begins at the puncta lacrimalia, which are small openings located in the inner corners of the upper and lower eyelids. When blinking, tears are spread across the surface of the eye and then collected by these puncta.

From the puncta, tears flow into tiny tubes called canaliculi, which lead to a larger structure known as the lacrimal sac. The lacrimal sac is situated in a groove on the side of the nose. From the lacrimal sac, tears descend through a narrow tube called the nasolacrimal duct.

The nasolacrimal duct empties into the nasal cavity, specifically into the inferior meatus of the nose. This is why crying can often lead to a runny nose, as the excess tears are drained into the nasal passages. The entire system is lined with mucous membrane and plays a crucial role in maintaining ocular health and comfort by removing debris and excess fluid from the eye's surface. Disruptions to this system can lead to various conditions, including excessive tearing (epiphora) or infections.