Orbit and Cavernous Sinus - LO 3

3. What are the components of the lacrimal system? What is the route of lacrimal fluid?

The lacrimal system begins with the lacrimal gland, located in the superolateral margin of the orbit. The lacrimal gland rests in the lacrimal fossa of the frontal bone, and sits between the aponeurosis for levator palpebrae superioris m. (medial to the gland) and the lateral rectus m. (inferior to the gland). The lacrimal gland secretes into the conjunctival sac along the lateral margin of the superior fornix. Tear fluid is conducted across the conjunctiva and accumulates in the lacrimal lake in the medial canthus. Deep to the lacrimal lake is a mound of skin, the lacrimal caruncle. Superior and inferior to the lacrimal lake are lacrimal papillae, which host small lacrimal puncta (pores) into which tear fluid flows. Fluid is conducted from the puncta via superior and inferior lacrimal canaliculi into the lacrimal sac, the proximal (superior) dilation of the nasolacrimal duct. The lacrimal sac lies in the lacrimal groove of the lacrimal bone. The nasolacrimal duct conducts tear fluid into the inferior nasal meatus.

Route of lacrimal fluid: 

lacrimal gland → conjunctival sac → lacrimal lake → lacrimal papillae → lacrimal puncta → lacrimal canaliculi (superior & inferior) → lacrimal sac → nasolacrimal duct → inferior nasal meatus