Carries tears from the lacrimal sac of the eye into the nasal cavity.
It has been suggested that this article be merged with nasolacrimal canal. (Discuss) Proposed since March 2024.
Nasolacrimal duct
The lacrimal apparatus. Right side.
Outline of bones of face, showing position of air sinuses.
Details
Identifiers
Latin
ductus nasolacrimalis
MeSH
D009301
TA98
A15.2.07.070
TA2
6859
FMA
9703
Anatomical terminology
[edit on Wikidata]
The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity.[1][2] The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backwards. The opening of the nasolacrimal duct into the inferior nasal meatus of the nasal cavity is partially covered by a mucosal fold (valve of Hasner or plica lacrimalis).[3]
Excess tears flow through the 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. This is for the same reason when applying some eye drops it is often advised to close the nasolacrimal duct by pressing it with a finger to prevent the medicine from escaping the eye and having unwanted side effects elsewhere in the body as it will proceed through the canal to the nasal cavity.
Like the lacrimal sac, the duct is lined by stratified columnar epithelium containing mucus-secreting goblet cells, and is surrounded by connective tissue.
^Herbert, Ronald A.; Janardhan, Kyathanahalli S.; Pandiri, Arun R.; Cesta, Mark F.; Miller, Rodney A. (2018). "Nose, Larynx, and Trachea". Boorman's Pathology of the Rat. Elsevier. pp. 391–435. doi:10.1016/b978-0-12-391448-4.00022-8. ISBN 978-0-12-391448-4. S2CID 80517730. The paired nasolacrimal ducts carry lacrimal secretions from the eye to the nasal cavity, and originate as oval openings near the edge of the medial canthus of the eyelids. Initially the duct is small and circular, but in the middle portion, the diameter increases and the appearance is more oblong and saccular. The diameter again decreases before the duct enters the ventrolateral nasal vestibule medial to the root of the incisor tooth approximately 2 mm caudal to the nares.
^"Medical Definition of PLICA LACRIMALIS". Merriam-Webster Medical Dictionary. 2020-05-08. Retrieved 2020-05-08. an imperfect valve at the opening of the nasolacrimal duct into the inferior meatus of the nose
The nasolacrimalduct (also called the tear duct) carries tears from the lacrimal sac of the eye into the nasal cavity. The duct begins in the eye socket...
Nasolacrimalduct obstruction is the obstruction of the nasolacrimalduct and may be either congenital or acquired. Obstruction of the nasolacrimal duct...
The canal containing the nasolacrimalduct is called the nasolacrimal canal. It is formed by indentations in the inferior nasal conchae, maxilla and lacrimal...
The lacrimal sac or lachrymal sac is the upper dilated end of the nasolacrimalduct, and is lodged in a deep groove formed by the lacrimal bone and frontal...
Nasolacrimalduct cysts are a cutaneous condition that is a developmental defect present at birth. Skin dimple List of cutaneous conditions Rapini, Ronald...
an infection of the lacrimal sac, secondary to obstruction of the nasolacrimalduct at the junction of lacrimal sac. The term derives from the Greek dákryon...
sac during excessive lacrimation. The fluid then flows through the nasolacrimalduct and into the nasopharynx. This drainage results in what is commonly...
consequence of narrowing or obstruction of the nasolacrimalduct, usually during prenatal development. Nasolacrimalduct obstruction disrupts the lacrimal drainage...
blinking of the eyelid causes rheum to be washed away with tears via the nasolacrimalduct. The absence of this action during sleep, however, results in a small...
From the punctum, tears will enter the lacrimal sac, then on to the nasolacrimalduct, and finally into the nasal cavity. An excess of tears, as caused...
nasal mucosa above the level of the mechanical obstruction at the nasolacrimalduct.[citation needed] When, due to an error of diagnosis, the technique...
restore the flow of tears into the nose from the lacrimal sac when the nasolacrimalduct does not function. A small incision is made on the side of the nose...
leads, tubing, wound dressings, silos for abdominal wall defects, and nasolacrimalduct obstruction. These medical-grade elastomers are also used in the manufacture...
glands on the eyelid), lacrimal duct cysts (cysts related to tear ducts), and nasolacrimalduct cysts (the nasolacrimalduct drains tears into the nose via...
lacrimal fossa. The lacrimal canaliculi, the lacrimal sac, and the nasolacrimalduct, by which the fluid is conveyed into the cavity of the nose, emptying...
to identify obstructions, for example in the lacrimal duct, nasal cavity or nasolacrimalduct. The typical procedure involves use of Technetium-99m colloid...
the orbital cavity, in which the lacrimal sac that drains into the nasolacrimalduct is located, is referred to as the lacrimal fossa (or fossa for the...
significant that low blood pressure occurs. Blood may also come up the nasolacrimalduct and out from the eye. Risk factors include trauma, including putting...
vocalizations such as speech The ear canals, for the sense of hearing The nasolacrimalducts, to carry tears from the lacrimal sac into the nasal cavity The anus...
through the lacrimal canaliculi on to the lacrimal sac, in turn to the nasolacrimalduct, which dumps them out into the nose. Lacrimal glands are also present...
canal opens into the inferior meatus of the nose and transmits the nasolacrimalduct. Horizontal section of nasal and orbital cavities. This article incorporates...
through the lacrimal canaliculi to the lacrimal sac, and thence via the nasolacrimalduct to the inferior nasal meatus of the nasal passage. A close up of a...
treatment if they are not visually significant. Strabismus, nystagmus and nasolacrimalduct obstruction occur more frequently in children with Down syndrome....
implicated in a variety of other infections, including those of the orbit, nasolacrimalduct and breast implants. It is a commensal of the human mouth, genital...
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