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Information about Lacrimal Gland

Lacrimal apparatus of the right eye. The lacrimal gland is to the upper right. The right side of the picture is towards the nose.
Tear system.

a = lacrimal gland
b = superior lacrimal punctum
c = superior lacrimal canal
d = lacrimal sac
e = inferior lacrimal punctum
f = inferior lacrimal canal
g = nasolacrimal canal
Latinglandula lacrimalis
subject #227 1028
Arterylacrimal artery
Nervelacrimal nerve
Dorlands/Elsevier g_06/12392431
The lacrimal glands are paired glands, one for each eye, that secrete the aqueous layer of the tear film. They are situated in the upper, outer portion of each orbit.

Anatomy

Each lacrimal gland is divided into orbital and palpebral portions by the aponeurosis of the Levator palpebrae superioris muscle, the portions are continuous with each other.
  • The orbital portion is the largest of the portions, and its convex superior surface is lodged in the lacrimal fossa of the orbit.
  • For the smaller palpebral portion, its inferior surface lies close to the eye; if the upper eyelid is everted, the palpebral portion can be seen.
The orbital portion contains fine interlobular ducts that unite to form 3 - 5 main excretory ducts, joining 5 - 7 ducts in the palpebral portion before the secreted fluid may enter on the surface of the eye.

Structure

The lacrimal gland is a tubuloacinar gland, it is made up of many lobules separated by connective tissue, each lobule contains many acini.

Each acinus consists of a grape-like mass of cells with their apices pointed to a central lumen.

The central lumen of many of the units united to form intralobular ducts, and then unite to from interlobular ducts.

Innervation

The sensory innervation to the lacrimal gland is from the lacrimal nerve of the trigeminal nerve.

The parasympathetic nerve supply originates from the lacrimal nucleus of the facial nerve in the pons. Just before reaching the geniculate ganglion, the facial nerve gives off the greater petrosal nerve. This nerve carries the parasympathetic secretomotor fibers through the pterygoid canal to the pterygopalatine ganglion. Here the fibers synapse and postganglionic fibers join the inferior orbital nerve, which travels through the inferior orbital fissure. Once it has traversed this opening, the parasympathetic secretomotor fibers join a branch of this inferior orbital nerve, namely the zygomatic nerve, part of which innervates the lacrimal gland.

The sympathetic postganglionic fibres originates from the superior cervical ganglion. They travel as a periarteriolar plexus with the middle meningeal artery, before they merge and form the deep petrosal nerve, which joins the greater petrosal nerve in the pterygoid canal. Together, greater petrosal and deep petrosal nerves form the nerve of the pterygoid canal (vidian nerve) and reach the pterygopalatine ganglion in the pterygopalatine fossa.In contrast to their parasympathetic counterparts, sympathetic fibers do not synapse. However they join the parasympathetic fibers, hence from this point on the routes of the parasympathetic and sympathetic fibers for the lacrimal gland are the same (inferior orbital nerve -> inferior orbital fissure -> zygomatic nerve -> lacrimal gland).

Blood supply

The lacrimal artery, derived from the ophthalmic artery supplies the lacrimal gland. Venous blood returns via the superior ophthalmic vein.

Pathology

Additional images


The ophthalmic artery and its branches.

Nerves of the orbit. Seen from above.

Sympathetic connections of the sphenopalatine and superior cervical ganglia.

The tarsal glands, etc., seen from the inner surface of the eyelids.

Alveoli of lacrimal gland.


See also

External links

 •  • [ e]
Accessory organs of the eye
GeneralEyebrow - Eyelid - Canthus - Eyelash - Ciliary glands - Orbital septum - Plica semilunaris - Meibomian gland
Lacrimal apparatusLacrimal lake - Lacrimal gland - Lacrimal canaliculi - Lacrimal punctum - Lacrimal papilla - Nasolacrimal duct
The lacrimal canaliculi, one in each eyelid, commence at minute orifices, termed puncta lacrimalia (or lacrimal punctum, or lacrimal point), on the summits of the papillae lacrimales, seen on the margins of the lids at the lateral extremity of the lacus lacrimalis.
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The lacrimal canaliculi, also known as the lacrimal canals or lacrimal ducts, are the small channels in each eyelid that commence at minute orifices, termed puncta lacrimalia, on the summits of the papillæ lacrimales, seen on the margins of the lids at the
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The lacrimal sac, is the upper dilated end of the nasolacrimal duct, and is lodged in a deep groove formed by the lacrimal bone and frontal process of the maxilla.

It is oval in form and measures from 12 to 15 mm.
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The lacrimal canaliculi, one in each eyelid, commence at minute orifices, termed puncta lacrimalia (or lacrimal punctum, or lacrimal point), on the summits of the papillae lacrimales, seen on the margins of the lids at the lateral extremity of the lacus lacrimalis.
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The lacrimal canaliculi, also known as the lacrimal canals or lacrimal ducts, are the small channels in each eyelid that commence at minute orifices, termed puncta lacrimalia, on the summits of the papillæ lacrimales, seen on the margins of the lids at the
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The canal containing the nasolacrimal duct is called the nasolacrimal canal.

It is formed by indentations in the inferior nasal conchae, maxilla and lacrimal bone.

See also

  • Orbit (anatomy)

Additional images


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Latin}}} 
Official status
Official language of: Vatican City
Used for official purposes, but not spoken in everyday speech
Regulated by: Opus Fundatum Latinitas
Roman Catholic Church
Language codes
ISO 639-1: la
ISO 639-2: lat
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Arteries are muscular blood vessels that carry blood away from the heart.[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life.
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The lacrimal artery arises close to the optic foramen, and is one of the largest branches derived from the ophthalmic artery: not infrequently it is given off before the artery enters the orbit.
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A nerve is an enclosed, cable-like bundle of axons (the long, slender projection of a neuron). Neurons are sometimes called nerve cells, though this term is technically imprecise since many neurons do not form nerves, and nerves also include the glial cells that
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The lacrimal nerve is the smallest of the three branches of the ophthalmic.

It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch which goes from the ophthalmic to the trochlear nerve.
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Elsevier, the world's largest publisher of medical and scientific literature, forms part of the Reed Elsevier group. Based in Amsterdam, the company has substantial operations in the UK, USA and elsewhere.
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gland is an organ in an animal's body that synthesizes a substance for release such as hormones, often into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland).
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Tear may refer to:
  • Tears, the water-based lubrication and cleansing fluid secreted around the eye
  • Tear (Wheel of Time), a nation in The Wheel of Time series by Robert Jordan
  • Tear Grants, a character in the video game Tales of the Abyss

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An eyelid is a thin fold of skin and muscle that covers and protects an eye. With the exception of the prepuce and the labia minora, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle retracts the eyelid to "open" the eye.
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Aponeuroses (απο, "away" or "of", and νευρον, "sinew") are membranes separating muscles from each other. They have a shiny, whitish-silvery color, and are histologically similar to tendons, but are very sparingly supplied with blood
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The levator palpebrae superioris (or levator muscle of upper eyelid) is the muscle in the orbit that elevates the superior (upper) eyelid.

Structure

The levator palpebrae superioris originates on the lesser wing of the sphenoid bone, just above the optic foramen.
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lacrimal fossa (or fossa for lacrimal gland), for the lacrimal gland.

External links

  • Stedman's/LWW 1519844
This article was originally based on an entry from a public domain edition of Gray's Anatomy.
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An eyelid is a thin fold of skin and muscle that covers and protects an eye. With the exception of the prepuce and the labia minora, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle retracts the eyelid to "open" the eye.
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A Interlobular duct is a gland duct which connects more than one lobule. It is smaller than an interlobar duct.

Examples of where it can be found include
  • pancreas[1][2]
  • mammary gland[3]
  • parotid gland[4][5]

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alveolar glands[1] (or saccular glands[2][3], or acinar glands[4], or acinous glands[5][6]).
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In anatomy, a lobe is a clear anatomical division or extension[1][2] that can be determined without the use of a microscope (at the gross anatomy level.) This is in contrast to a lobule, which is a clear division only visible histologically.
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Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, muscle, and nervous tissue.) It is largely a category of exclusion rather than one with a precise definition, but all or most tissues in this category are similarly:
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An acinus (adjective: acinar, plural acini) refers to the berry-shaped termination of an exocrine gland, where the secretion is produced.

They are found in many organs, including:
  • the stomach[1]
  • the sebaceous gland of the scalp

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Lumen can mean:
  • Lumen (unit), the SI unit of luminous flux
  • Lumen (anatomy), the cavity or channel within a tubular structure
  • Thylakoid lumen, the inner membrane space of the chloroplast

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An intralobular duct is the portion of an exocrine gland inside a lobule, leading directly from intercalated duct to an interlobular duct.

They can be seen in:
  • pancreas[1][2][3][4]
  • salivary glands[5]

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A Interlobular duct is a gland duct which connects more than one lobule. It is smaller than an interlobar duct.

Examples of where it can be found include
  • pancreas[1][2]
  • mammary gland[3]
  • parotid gland[4][5]

..... Click the link for more information.
The lacrimal nerve is the smallest of the three branches of the ophthalmic.

It sometimes receives a filament from the trochlear nerve, but this is possibly derived from the branch which goes from the ophthalmic to the trochlear nerve.
..... Click the link for more information.
The trigeminal nerve (the fifth cranial nerve, also called the fifth nerve or simply V) is responsible for sensation in the face. It is similar to the spinal nerves C2–S5, which are responsible for sensation in the rest of the body.
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parasympathetic nervous system (PSNS) is one of three divisions of the autonomic nervous system (ANS). The ANS -a subdivision of the peripheral nervous system (PNS)- is subdivided into the sympathetic (SNS), parasympathetic (PSNS) and enteric (bowels) nervous system (ENS).
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