Lacrimal Bone · What is it, Location, Function, and More

The main function of the lacrimal bone is to provide structural support to the lacrimal apparatus, or the eye’s tear-producing system. The lacrimal bone is divided by a vertical ridge called the posterior lacrimal crest. This crest creates a hollow depression in the surface of the lacrimal bone (i.e., lacrimal sulcus) that helps form the canal for the nasolacrimal duct. The most superior and dilated part of the nasolacrimal duct is called the lacrimal sac; this is a structure where tears accumulate as they drain from the eye. The posterior lacrimal crest has a hook-like projection called the lacrimal hamulus, which articulates with the frontal process of the maxillary bone, creating an opening for the nasolacrimal duct to drain into the nose. Specifically, lacrimal fluid flows into the inferior nasal meatus, which is located in the inferior nasal concha. This site of drainage explains why individuals typically experience a “runny nose” when they cry. 

In addition, another function of the lacrimal bone is to provide an attachment point for the orbicularis oculi muscle, which is responsible for closing the eyelids and helps promote tear drainage.