The Lacrimal Gland

Horner's muscle fibers do not ___ the lacrimal sac.

"Pump"

Vertically, how long is the lacrimal sac?

10-12mm long

How long is the nasolacrimal duct?

12-15mm long

What % of tears evaporate? What % drain to the nasal cavity?

25%; 75%

What is the Jones test?

A test using Fluorescein Sodium to see how well stained tears drained.

What are the secreting units of exocrine glands called?

Acini

What is it called when light is bent first in eye?

Air-Tear Film Refraction

The vertical part of the canaliculi terminate at a swelling or ____

Ampulla

The Lacrimal Gland is divided into two parts by the _____.

Aponeurosis of the Levator Palpebrae Superioris

What are tear reservoirs? What three areas are tear reservoirs?

Areas that tend to collect tears; Fornices, the lacrimal lake, and the superior and inferior marginal tear strips

Where are the Lacrimal Glands of Wolfring found? How many are found in the eye and where?

At the end of tarsal plate; 2-5 in upper eyelid 2 in lower eyelid

Tears comes from _____. What does it contain?

Blood plasma; Growth factors, Antibodies, anti-inflammatory factors

___ ectoderm detaches from its connection to ____ ectoderm to become a solid cord. The cord hollows out to form the ____, ____, and ____

Buried; Surface; Lacrimal canaliculi, sac, and duct.

Tears enter the puncta by ______, but as the _____ are pumped, tear fluid is driven toward the ______.

Capillary attraction; canaliculi; lacrimal sac

The _______ terminates on the superior lacrimal sac. The inferior lacrimal sac is continuous with the beginning of the _____.

Common canaliculus; Nasolacrimal duct

What does "compound" in Compound Tubuloacinar mean? What does the "Tubloacinar" mean?

Compound implies more than one duct.; The secreting units have a tubular shape and an acinar (splays out) shape.

What two characteristics are used to described the serous secreting units of the gland?

Compound, Tubulo-Alveolar (or Tubuloacinar)

The main lacrimal gland is an extension of the ____ into the orbit and the ____ ____ layer of the eyelid.

Conjuctiva; Submuscular Areloar

Reflex arc of corneal nerves in blink:

Corneal Nerv (CN V) >>> Directly to CN VII >>> causes orbiculairs oculi muscle to blink

The main lacrimal gland begins as conjuctival fornix surface ____, which grows into the underlying _____.

Ectoderm; Mesenchyme

The lacrimal gland receives ____ signal from the CNS that is ____

Efferent; Autonomic

What do we use to stain tears that allows up to see dry spots on eye?

Fluorescein Sodium

_______ fibers originate from the lacrimal sac fascia, as well as from the posterior lacrimal crest.

Horner's muscle

The horizontal and vertical parts are surrounded by the ____ muscle of the _______.

Horner's; orbicularis oculi

Where are the Lacrimal Glands of Krause found? How many are found in the eye and where?

In the cup-de-sac (fornix) of conjuctiva; 42 in upper fornix 6-2 in lower fornix

The main lacrimal gland is located where?

In the superior-lateral orbit against an indentation in the frontal bone called the Lacrimal Fossa

The nasolacrimal duct runs within the canal and drains into the _____.

Inferior nasal meatus

2 parts of the nasolacrimal duct

Interosseous & Intrameatal

Which part of the nasolacrimal duct is surrounded by the bones of the bony nasolacrimal canal?

Interosseous part

Which part of the nasolacrimal duct runs under the mucous membrane of the inferior meatus until it ends at its opening (ostium)

Intrameatal

What does the caruncle do? What tear reservoir is here?

It exists to position tears more anteriorly on ocular surface to allow better drainage; Lacrimal Lake

The lateral portion of the eyelid is supplied by the ____.

Lacrimal Artery

The horizontal canaliculi run from the swelling travel medially, before penetrating the ______.

Lacrimal Fascia

The lacrimal sac is surrounded by the connective tissue _____.

Lacrimal Fascia

Both canaliculi unite at the _______ to form a ______

Lacrimal Fascia; Common Canaliculus

The lacrimal sac sits within the ____ of the orbit

Lacrimal Fossa

Accessory lacrimal glands add to the volume of tear fluid. There are two kinds:

Lacrimal Glands of Wolfring & Lacrimal Glands of Krause.

General innervation of the lacrimal gland:

Lacrimal Nerve >> Ophthalmic Nerve (V1) >>Trigeminal Nerve (CN V)

The sympathetic innervation of the lacrimal gland travels with the ____.

Lacrimal artery

The tubes that begin at the puncta are called...

Lacrimal canaliculi

The nasolacrimal canal is formed mostly by the anterior _____ of maxilla, but also by the ______

Lacrimal groove; Inferior nasal concha

What connective tissue rings help keep the puncta open?

Lacrimal papillae

What are the holes through which drainage occurs in the eye? How large are they?

Lacrimal puncta; 0.2-o.3mm in diameter

The gland is supplied by the glandular branches of the ____ artery and drained by the ____ vein.

Lacrimal; Lacrimal

The 2 divisions of the lacrimal gland are further subdivided into ____ by _____ _____ _____ layers

Lobules; Interlobular Connective Tissue

_______ surface ectoderm grows and meets ______ surface ectoderm. The fused ectoderm then becomes ____ as both processes continue to grow.

Maxillary process; Frontonasal process; buried

The nasolacrimal duct travels through the _____ which begins at the bottom of the fossa for the _____.

Nasolacrimal duct; lacrimal sac

The trigger that causes you to blink when eye is dry is due to ____.

Osmolarity

Most of the lacrimal sac is posterior to the medial ______.

Palpebral ligament

The autonomic signal to the lacrimal gland is mainly ____ via the ____

Parasympathetic; Facial Nerve (CN VII)

Lymphatic vessels of the lacrimal gland drain to the ____ ____.

Parotid Nodes

The lacrimal sac and nasolacrimal ducts are composed of _______. It is similar to the nasal cavity, except that ____ are absent and _____ are present.

Pseudo-stratified epithelium; Cilia, Goblet Cells

How is a tear drainage blockage treated?

Saline is pushed into canuliculis

Dryness causes light to ____.

Scatter

The canaliculi, like the marginal conjuctiva are lined with cells that are....

Stratified, squamous, non-keratinized epithelium

2 division of the lacrimal gland are? Which one is larger?

Superior (Orbital) & Inferior (Palpebral); The Superior (Orbital) is larger

How far away are the puncta from the medial canthus?

Superior Punctum in upper eyelid is 6.0mm away from medial canthus when eyes are closed. Inferior Punctum in lower eyelid is 6.5mm away from medial canthus when eyes are closed.

Both puncta are in line with the ___ openings.

Tarsal gland

Where do the tears drain to out of the lacrimal gland? Which portion do they drain from?

The drain into the superior-lateral conjunctival fornix through the palpebral (inferior) portion

By what bones is the lacrimal fossa for the lacrimal sac limited?

The lacrimal fossa is limited by the posterior lacrimal crest of lacrimal bone and anterior lacrimal crest of maxillary bone.

How is the tear film pushed medially towards the drainage apparatus?

The lateral parts of eyelids meet each other before the medial parts.

Which tear film breaks up between blinks?

The precorneal tear film

There are approximately HOW many ducts that the numerous acini drain into?

Twelve

Where is it, and what is the purpose of the valve of Hasner?

Valve of Hasner is located at the ostium of the nasolacrimal duct. Its purpose it to prevent retrograde movement of fluid and air int he nasal cavity back up the duct.

What is Epiphora?

When tears drain down the face

Explain how "positive canalicular pressure" works.

When the orbicularis contracts, the puncta are pulled medially, the ampullae narrow, and the canaliculi shorten as tears are pumped into the lacrimal sac.