Nasolacrimal ducts

Definition

Nasolacrimal ducts are small channels that drain tears from the lacrimal sac into the nasal cavity. They play a crucial role in maintaining eye moisture and can be pathways for respiratory infections.

5 Must Know Facts For Your Next Test

1. Nasolacrimal ducts connect the eyes to the nasal cavity, providing a route for potential pathogen transmission.
2. Blockage or infection of these ducts can lead to dacryocystitis, an inflammation of the lacrimal sac.
3. Normal microbiota of the nasolacrimal ducts includes bacteria such as Staphylococcus epidermidis and Corynebacterium species.
4. Tears contain antimicrobial proteins like lysozyme which help protect against infections entering through these ducts.
5. Conditions like sinus infections can affect the nasolacrimal ducts, leading to symptoms such as excessive tearing or discharge.

Review Questions

• What is the primary function of nasolacrimal ducts?
• How do nasolacrimal ducts contribute to respiratory tract infections?
• Name two types of normal microbiota found in the nasolacrimal ducts.

Related terms

Lacrimal Sac: A structure that collects tears from the eye before they drain into the nasolacrimal duct.

Dacryocystitis: Inflammation and infection of the lacrimal sac.

Lysozyme:

An enzyme found in tears that has antibacterial properties.