lacrimal sac


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sac

 [sak]
a baglike organ or structure; see also bag, pocket, and pouch.
air s's (alveolar s's) the spaces into which the alveolar ducts open distally, and with which the alveoli communicate; see also lung.
amniotic sac the sac formed by the amnion, enclosing the fetus suspended in amniotic fluid; popularly known as the bag of waters.
conjunctival sac the potential space, lined by conjunctiva, between the eyelids and the eyeball.
endolymphatic sac the blind, flattened cerebral end of the endolymphatic duct.
hernial sac the peritoneal pouch that encloses protruding intestine.
lacrimal sac the dilated upper end of the nasolacrimal duct; see also lacrimal apparatus.
yolk sac the extraembryonic membrane connected with the midgut; in vertebrates below true mammals, it contains a yolk mass.
Yolk sac in a developing embryo. From Applegate, 2000.

lac·ri·mal sac

[TA]
the dilated upper portion of the nasolacrimal duct into which the two lacrimal canaliculi empty.

lac·ri·mal sac

(lak'ri-măl sak) [TA]
The upper portion of the nasolacrimal duct into which empty the two lacrimal canaliculi.
Synonym(s): saccus lacrimalis [TA] , dacryocyst, tear sac.

lacrimal sac

The small bag lying under the tissues just inwards and below the inner corner of the eye. Tears drain into the lacrimal sac before being discharged down the nasolacrimal duct into the nose.

Lacrimal sac

The dilated upper end of the nasolacrimal duct in which the lacrimal ducts empty.

lacrimal apparatus

The system involved in the production and conduction of tears. It consists of the lacrimal gland and accessory lacrimal glands (glands of Krause and Wolfring); the eyelid margins; and the two puncta lacrimae. Each punctum is a small round or oval aperture situated on a slight elevation at the inner end of the upper and lower lid margin (lacrimal papilla) and forms the entrance to the canaliculi. Each canaliculus consists of a vertical portion of about

lacrimal apparatus

The system involved in the production and conduction of tears. It consists of the lacrimal gland and accessory lacrimal glands (glands of Krause and Wolfring); the eyelid margins; and the two puncta lacrimae. Each punctum is a small round or oval aperture situated on a slight elevation at the inner end of the upper and lower lid margin (lacrimal papilla) and forms the entrance to the canaliculi. Each canaliculus consists of a vertical portion of about 2 mm long and then bends inward for some 8 mm, the upper one being slightly shorter. The canaliculi pierce the lacrimal fascia (i.e. the periorbita covering the lacrimal sac or tear sac) and unite (forming the common canaliculus) to enter a small diverticulum of the sac called the sinus of Maier. The lacrimal sac is closed above and open below where it is continuous with the nasolacrimal duct which extends over some 1.5 cm in length to Hasner's valve (or Bianchi's valve or plica lacrimalis) (folds of mucous membrane) at the inferior meatus of the nose. The inferior opening of the duct is called the ostium lacrimale (Fig. L1). See dacryocystitis; epiphora; lacrimal fistula; fossa for the lacrimal sac; Sjögren's syndrome; tear duct; dye dilution test; Jones II test; valve of Krause.
Fig. L1 Lacrimal apparatusenlarge picture
Fig. L1 Lacrimal apparatus
References in periodicals archive ?
This view is shared by another study consisting of 46 endonasal DCR surgeries.11 Inadequate exposure of lacrimal sac and injury to surrounding nasal mucosa are considered to be the common causes of surgical failure.
CDCR was performed in 17 eyes, whereas CR was performed in 2 eyes (one eye due to upper and middle lacrimal system excision accompanied by tumor excision and one eye due to upper-lower canalicular and lacrimal sac burn after laser DCR).
Both upper and lower punctum were dilated and 20 gauge vitrectomy light was passed through the upper punctum into the lacrimal sac. Nasal packing was removed and nasal cavity was entered with 4mm 00 Hopkin Karl Storz rigid nasal endoscope attached to an endoscopic video camera (Stryker endoscopy system).
The site of obstruction was evaluated with regurgitation and lacrimal sac irrigation test.
The lacrimal sacs can't drain your tears fast enough.
Pathological Examination of Lacrimal Sac. A probe was inserted into the lacrimal sac from the lacrimal punctum to determine the precise location of the lacrimal sac.
The volunteer was in the supine position, with the eyeball gazing at the above location then closed the eyes, a water bladder filled with 60 ml distilled water was put on the eye region, and the ultrasonic probe was placed just above the area of lacrimal sac, with the indicating line perpendicular to the eyelid .
While primarily a nasal neoplasm, cases of an inverted papilloma involving the temporal bone, pharynx, nasopharynx, and lacrimal sac have been reported.
Though several intra-nasal pleomorphic adenomas have been described, to our knowledge this is the first reported case of a pleomorphic adenoma arising from the mucosa of lateral nasal wall over the lacrimal bone without invading the lacrimal sac.
The lacrimal pump mechanism involves contraction of the orbicularis muscle to close the eye, which creates negative pressure in the lacrimal sac. Since part of its fibres are connected to the fascia, which envelops the sac, this contraction 'opens up' the sac by enlarging it.
Specimen.--The ocular adnexa are those anatomic structures that surround the eyeball, protect it from injury, and facilitate its functioning; this includes the conjunctiva (palpebral and bulbar), orbital cavity soft tissues, main lacrimal gland, accessory lacrimal glands, nasolacrimal drainage system (including the upper and lower canaliculi, lacrimal sac, and nasolacrimal duct), and the eyelid.