Lacrimal drainage system Flashcards
Where is the lacrimal gland located?
The lacrimal gland is located in the upper outer part of each orbit
What are the accessory lacrimal glands called?
The accessory lacrimal glands are called the glands of Wolfring and glands of Krause.
What is the function of the Meibomian glands?
The Meibomian glands produce the lipid layer of the tear film, which prevents evaporation of tears.
How do goblet cells contribute to the tear film?
Goblet cells, located in the conjunctiva, produce mucin, which helps spread the tear film evenly across the surface of the eye
Describe the process of tear collection in the lacrimal drainage system.
Tears are collected at the inner corner of the eye by the puncta, small openings located on the upper and lower eyelids. They then flow through the canaliculi into the common canaliculus, which directs the tears into the lacrimal sac.
What is the function of the common canaliculus in the lacrimal drainage system?
The common canaliculus is formed by the merger of the upper and lower canaliculi, directing tears into the lacrimal sac.
Describe the composition and function of the tear film layers.
The tear film has three layers: the lipid layer (produced by Meibomian glands, prevents evaporation), the aqueous layer (produced by the lacrimal gland, provides moisture and nutrients), and the mucin layer (produced by goblet cells, spreads the tear film evenly).
What is the role of the lacrimal pump mechanism in tear elimination?
The lacrimal pump mechanism, involving the orbicularis oculi muscle, compresses and shortens the canaliculi, creating a positive pressure that forces tears down the nasolacrimal duct into the nose.
