lacrimal apparatus 2

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A part of eye ball.

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Lacrimal apparatus:

Lacrimal apparatus 1 shabana ali

Learning objectives:

Learning objectives Enumerate components of lacrimal apparatus Describe each component of lacrimal apparatus. 2 shabana ali

Components of lacrimal apparatus:

Components of lacrimal apparatus Lacrimal gland Lacrimal puncta Lacrimal cannaliculi Lacrimal sac Naso lacrimal duct 3 shabana ali

Components of lacrimal apparatus:

Components of lacrimal apparatus 4 shabana ali

Lacrimal gland:

Lacrimal gland It is situated above the eyeball in the anterior and upper part of the orbit posterior to the orbital septum shabana ali 5

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Parts of the Lacrimal gland:

Parts of the Lacrimal gland 1.the larger orbital part is in a depression, the lacrimal fossa, in the frontal bone; 2.the smaller palpebral part is inferior to levator palpebrae superioris ,in the superolateral part of the eyelid shabana ali 7

Lacrimal gland isdrained by a series of 8–12 small ducts:

Lacrimal gland isdrained by a series of 8–12 small ducts Ducts open into the lateral part of the superior conjunctival fornix This secretion is spread over the surface of the eye by the action of the lids. 8 shabana ali

Tears are produced by lacrimal gland to lubricate the cornea and sclera :

Tears are produced by lacrimal gland to lubricate the cornea and sclera 9 shabana ali

Tears travel towards medial angle of eye :

Tears travel towards medial angle of eye 10 shabana ali

Lacrimal canaliculi :

Lacrimal canaliculi Two canals that begin as a lacrimal punctum (or pore) in the margin of the eyelid open into the lacrimal sac. shabana ali 11

Lacrimal sac :

Lacrimal sac Is the upper dilated end of the nasolacrimal duct. opens into the inferior meatus of the nasal cavity. shabana ali 12

Identify the parts of lacrimal apparatus:

Identify the parts of lacrimal apparatus 13 shabana ali

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Nasolacrimal duct:

Nasolacrimal duct The nasolacrimal duct, is about 0.5 in (12 mm) in length. location : in a bony canal in the medial wall of the orbit. The duct descends downward, backward, and laterally in a bony canal . opens into : the inferior meatus of the nose. 15 shabana ali

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tears are drained by way of the lacrimal canaliculi through lacrimal punctum:

tears are drained by way of the lacrimal canaliculi through lacrimal punctum 17 shabana ali

Mechanism of drainage of tears:

Mechanism of drainage of tears Blinking… the orbicularis oculi muscle contracts . The small lacrimal part of the muscle compresses the lacrimal sac . Therefore , fluid is forced into the nasolacrimal duct which drains into the inferior meatus of the nasal cavity. 18 shabana ali

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Nerve supply:

Nerve supply sympathetic and parasympathetic. … secretomotor 20 shabana ali

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derived from the lacrimal nucleus of the facial nerve. The preganglionic fibers reach the pterygopalatine ganglion ( sphenopalatine ganglion) via the nervus intermedius and its great petrosal branch and via the nerve of the pterygoid canal shabana ali 21

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The postganglionic fibers leave the ganglion and join the maxillary nerve. They then pass into its zygomatic branch and the zygomaticotemporal nerve. They reach the lacrimal gland within the lacrimal nerve. 22 shabana ali

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The sympathetic postganglionic nerve supply is from the internal carotid plexus travels in the deep petrosal nerve, the nerve of the pterygoid canal, the maxillary nerve, the zygomatic nerve, the zygomaticotemporal nerve, and finally the lacrimal nerve 24 shabana ali

Crocodile tears syndrome (Bogorad's syndrome:

Crocodile tears syndrome ( Bogorad's syndrome is spontaneous lacrimation during eating caused by a lesion of the facial nerve proximal to the geniculate ganglion. It follows facial paralysis and is due to misdirection of regenerating parasympathetic fibers, which formerly innervated the salivary glands, to the lacrimal glands. 25 shabana ali

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