Lacrimal System Flashcards
(20 cards)
What is the primary function of tears?
Keep the corneal epithelium moist
The secondary function is to lubricate the anterior globe so it moves freely beneath the lids.
List the layers of the tear film.
- Deep mucin layer
- Middle aqueous layer
- Superficial lipid layer
What glands are responsible for the middle aqueous layer of the tear film?
Main and accessory lacrimal glands
What is the structure of the lacrimal gland?
C shaped structure, which wraps around the LPS aponeurosis
How many glands extend from the lacrimal gland into the conjunctival fornix?
Approximately 12 glands
What supplies blood to the lacrimal gland?
- Lacrimal artery
- Infraorbital artery
What is the main sensory innervation of the lacrimal gland?
Lacrimal nerve from V1
Where do the preganglionic parasympathetic fibers that innervate the lacrimal gland originate?
Facial nerve fibers originating in the lacrimal nucleus
What pathway do postganglionic parasympathetic fibers take to reach the lacrimal gland?
They piggyback along V2 then reach the gland with the lacrimal nerve.
True or False: Accessory lacrimal glands are responsible for the main tear production.
False
Accessory lacrimal glands provide background tear production.
What is the drainage pathway for tears after they are secreted onto the eye?
Puncta -> canaliculi -> nasolacrimal sac -> nasolacrimal duct -> inferior meatus of nasal cavity
What can insufficient lipid layer in the tear film lead to?
Dry eye due to aqueous evaporation
What clinical condition can result from blockage of the nasolacrimal duct?
Dacrocystitis
What is the role of the deep mucin layer in the tear film?
Produced by conjunctival goblet cells
What is the consequence of dysfunction in the layers of the tear film?
Can lead to dry eye
What are the accessory lacrimal glands scattered throughout?
Conjunctival fornices
What is the role of the lacrimal reflex?
Forms the efferent pathway of lacrimal reflex
What is the anatomical division of the lacrimal gland?
Divided into orbital and palpebral parts
What are the main causes of exposure keratopathy?
Corneal damage secondary to dry eye
Fill in the blank: The lacrimal gland is innervated by the _______.
Facial nerve
