lacrimal sac

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Related to Nasolacrimal sac: lacrimal duct

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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

lac·ri·mal sac

[TA]
the dilated upper portion of the nasolacrimal duct into which the two lacrimal canaliculi empty.
Farlex Partner Medical Dictionary © Farlex 2012

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.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

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.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

Lacrimal sac

The dilated upper end of the nasolacrimal duct in which the lacrimal ducts empty.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

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
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
Rodent ulcer of inner canthal region and subsequent scarring after irradiation may cause obstruction of nasolacrimal sac or duct.
The morphology of nasolacrimal sac was normal in 12 patients, distended in 17 patients and fibrosed (Fig.