Lacrimal System & Drainage

Question 1

Outer Lipid Layer

Answer 1

• Thinnest layer
• Oily layer secreted by meibomian glands on eyelids situated on posterior surface of lid within tarsal plate
• Job: prevent excessive evaporation of tears, acts as lubricants to smoothen eyelid movements on globe

Question 2

Describe the Middle Aqueous Layer

Answer 2

• Secreted by lacrimal glands located in upper outer quadrant of eye socket
• Main functioning layer & thickest layer
• Supplies O2 to avascular corneal epithelium- essential for regeneration
• Contains antibacterial enymes- which helps prevent infection on corneal surface
• Smooths corneal surface- act as natural CL on eye
• Washes away debris

Question 3

Inner Mucin Layer

Answer 3

• Mucus secreted by conj goblet cells
• Converts corneal surface from hydrophobic to hydrophilic and allows wetting (tear film to stay on eye)