a duct that carries tears from the lacrimal sac to the nasal cavity
The tear duct.
The nasolacrimal duct carries tears from the lacrimal sac into the nasal cavity. The opening of the nasolacrimal duct into the inferior nasal meatus is partially covered by a mucosal fold. Excess tears flow through nasolacrimal duct which drains into the inferior nasal meatus. This is the reason the nose starts to run when a person is crying or has watery eyes from an allergy, and why one can sometimes taste eye drops. Like the lacrimal sac, the duct is lined by stratified columnar epithelium containing mucus-secreting goblet cells, and is surrounded by connective tissue. Obstruction of the nasolacrimal duct, known as dacryostenosis, leads to the excess overflow of tears called epiphora. A congenital obstruction can cause cystic expansion of the duct and is called a dacrocystocele or Timo cyst. Persons with dry eye conditions can be fitted with punctal plugs that seal the ducts to limit the amount of fluid drainage and retain moisture. The canal containing the nasolacrimal duct is called the nasolacrimal canal. In humans, the tear ducts in males tend to be larger than the ones in females.
The numerical value of nasolacrimal duct in Chaldean Numerology is: 6
The numerical value of nasolacrimal duct in Pythagorean Numerology is: 4
Images & Illustrations of nasolacrimal duct
Find a translation for the nasolacrimal duct definition in other languages:
Select another language:
Discuss these nasolacrimal duct definitions with the community:
Word of the Day
Would you like us to send you a FREE new word definition delivered to your inbox daily?
Use the citation below to add this definition to your bibliography:
"nasolacrimal duct." Definitions.net. STANDS4 LLC, 2017. Web. 28 May 2017. <http://www.definitions.net/definition/nasolacrimal duct>.