lacrimal apparatus
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apparatus
[ap″ah-rat´tus] (pl. appara´tus, apparatuses)an arrangement of a number of parts acting together to perform a special function.
Golgi apparatus see golgi apparatus.
juxtaglomerular apparatus a collective term for the juxtaglomerular cells in a nephron.
lacrimal apparatus see lacrimal apparatus.
Wangensteen's apparatus a nasal suction apparatus connected with a duodenal tube for aspirating gas and fluid from stomach and intestine.
lacrimal
[lak´rĭ-mal]pertaining to tears.
lacrimal apparatus a group of organs concerned with the production and drainage of tears; it is a protective device that helps keep the eye moist and free of dust and other irritating particles. The lacrimal gland, which secretes tears, lies over the upper, outer corner of the eye; its excretory ducts branch downward toward the eyeball. A constant stream of tears washes down over the front of the eye and is drained off through two small openings located in the inner corner of the eye. Through these openings the tears pass into the lacrimal canaliculus, then through the lacrimal sac into the nasolacrimal duct and finally into the nasal cavity.
The lacrimal apparatus. From Jarvis, 1996.
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 ap·pa·ra·tus
[TA]the structures that, with the conjunctival sac, produce and provide drainage for lacrimal fluid (tears), consisting of the lacrimal gland, the lacrimal lake, the lacrimal canaliculi, the lacrimal sac, and the nasolacrimal duct.
Synonym(s): apparatus lacrimalis [TA]
Farlex Partner Medical Dictionary © Farlex 2012
lac·ri·mal ap·pa·ra·tus
(lak'ri-măl ap'ă-rat'ŭs) [TA]Consisting of the lacrimal gland, the lacrimal lake, the lacrimal canaliculi, the lacrimal sac, and the nasolacrimal duct.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
lacrimal apparatus
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LACRIMAL APPARATUS: Anterior view
Structures concerned with the secretion and conduction of tears. It includes the lacrimal gland and its secretory ducts, lacrimal canaliculi, lacrimal sac, and nasolacrimal duct, which empties into the nasal cavity. See: illustration
Patency of the lacrimal duct may be tested by placing a dilute solution of sugar in the conjunctival sac; if the duct is patent, the individual will report the sensation of sweetness in the mouth; if not, the sugar will not be perceived.
Medical Dictionary, © 2009 Farlex and Partners
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.
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Fig. L1 Lacrimal apparatus
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
lac·ri·mal ap·pa·ra·tus
(lak'ri-măl ap'ă-rat'ŭs) [TA]Consisting of the lacrimal gland, the lacrimal lake, the lacrimal canaliculi, the lacrimal sac, and the nasolacrimal duct.
Medical Dictionary for the Dental Professions © Farlex 2012