Nasolacrimal duct

Nasolacrimal duct is a part of the human anatomy that is responsible for the drainage of tears from the eye to the nose. It is a thin tube that extends from the lacrimal sac to the inferior nasal meatus, allowing the flow of tears from the lacrimal punctum into the nose.

Anatomy

The nasolacrimal duct is approximately 18mm in length and is located within the maxilla. It begins at the lacrimal sac and ends at the inferior nasal meatus. The duct is lined with non-keratinized stratified squamous epithelium and contains goblet cells, which produce mucus to facilitate the flow of tears.

Function

The primary function of the nasolacrimal duct is to drain tears from the eye to the nose. This is achieved through the lacrimal apparatus, which consists of the lacrimal gland, lacrimal canaliculi, lacrimal sac, and the nasolacrimal duct. The tears produced by the lacrimal gland flow through the lacrimal canaliculi into the lacrimal sac, and from there, they are drained into the nose via the nasolacrimal duct.

Clinical significance

Blockage of the nasolacrimal duct, known as dacryocystitis, can lead to excessive tearing, known as epiphora, or infection of the lacrimal sac, known as dacryocystitis. Treatment for these conditions may include antibiotics, warm compresses, massage, or surgical intervention in the form of dacryocystorhinostomy, which creates a new pathway for tear drainage.

See also

• Lacrimal apparatus
• Dacryocystitis
• Epiphora