Nasolacrimal duct

Nasolacrimal duct
Nasolacrimal duct
Gray896.png
The lacrimal apparatus. Right side.
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Outline of bones of face, showing position of air sinuses.
Latin d. nasolacrimalis
Gray's subject #227 1029
MeSH Nasolacrimal+Duct

The nasolacrimal duct (sometimes called the tear duct) carries tears from the lacrimal sac into the nasal cavity. 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,[1] 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.

Contents

Additional images

  • Roof, floor, and lateral wall of left nasal cavity.


See also

External links

References

  1. ^ Blocked tear ducts in infants, Pediatric Views, June 2006 http://www.childrenshospital.org/views/june06/blocked_tear_ducts.html


v · d · eHead and neck anatomy – accessory visual structures (TA 15.2.7, TH H3.11.08.6, GA 10.1021)
Eyelid

Tarsus (Meibomian pelicle) • Medial palpebral ligament • Epicanthic fold • Meibomian gland • Ciliary glands • Eyelash

Palpebral fissure • Canthus

Gland of Zeis
Lacrimal apparatus
Lacrimal lake • Lacrimal gland • Lacrimal canaliculi • Lacrimal punctum • Lacrimal papilla • Nasolacrimal duct • Lacrimal sac • Lacrimal caruncle • Krause's glands
Other

Periorbita • Orbital septum • Tenon's capsule • Suspensory ligament of eyeball

Eyebrow

Conjunctiva (Plica semilunaris)

Extraocular muscles (Trochlea of superior oblique)

M: EYE

anat(g/a/p)/phys/devp/prot

noco/cong/tumr, epon

proc, drug(S1A/1E/1F/1L)

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Look at other dictionaries:

  • nasolacrimal duct — n a duct that transmits tears from the lacrimal sac to the inferior meatus of the nose called also nasal duct * * * the duct that passes through the hole (nasolacrimal canal) in the palatine bone of the skull. It drains the tears away from the… …   Medical dictionary

  • Nasolacrimal duct cyst — Nasolacrimal duct cysts are a cutaneous condition that is a developmental defect present at birth.[1] See also Skin dimple List of cutaneous conditions References ^ Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2… …   Wikipedia

  • nasolacrimal duct — the duct that passes through the hole (nasolacrimal canal) in the palatine bone of the skull. It drains the tears away from the lacrimal apparatus into the inferior meatus of the nose …   The new mediacal dictionary

  • nasolacrimal duct — noun a duct that carries tears from the lacrimal sac to the nasal cavity • Hypernyms: ↑duct, ↑epithelial duct, ↑canal, ↑channel * * * Anat. a membranous canal extending from the lacrimal sac to the nasal cavity, through which tears are discharged …   Useful english dictionary

  • nasolacrimal duct — noun The tear duct …   Wiktionary

  • nasolacrimal duct — Anat. a membranous canal extending from the lacrimal sac to the nasal cavity, through which tears are discharged into the nose. See diag. under lacrimal gland. * * * …   Universalium

  • congenital nasolacrimal duct obstruction — obstruction of the nasolacrimal duct of an infant as a result of incomplete canalization; affected children have tears and debris on the cheek below the duct …   Medical dictionary

  • Проток Носослезный (Nasolacrimal Duct) — проток, проходящий в одноименном канале (nasolacrimal canal). По нему слеза течет из слезного мешка в нижний носовой ход. Источник: Медицинский словарь …   Медицинские термины

  • Nasolacrimal canal — Bone: Nasolacrimal canal The lacrimal apparatus. Right side …   Wikipedia

  • nasolacrimal groove — an epithelial ingrowth parallel with but medial to the nasomaxillary groove of the embryo, which marks the site of later development of the nasolacrimal duct …   Medical dictionary

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