physiology of the tears and lacrimal apparatus

The lipid layer of tear film

• lubricates the eyelids as it pass over the globe.

• lubricates the corneal surface.

• adhere the tear film to the cornea.

• washes away foreign bodiesfrom corneal epithelium.

Mucin layer adsorbed by the glycocalyx of the ocular srface cells and act as

• layer that smooth the eyelid movementThis is a wrong answer

• interface that facilitates adhesion

• layer that retards evaporationThis is a wrong answer

• interface that provides nutrientsThis is a wrong answer

Layer of the tear film adherent to the corneal epithelium

• Lipid

• Mucin

Major source of mucin layer of the tear film

• Meibomian gland

• Goblet cell

The tear film covers the anterior surface of the _____.

• Iris

• sclera

• cornea

• eyelid

What is the major source of the aqueous layer of the tear film?

• Lacrimal gland

• Goblet cell

• Meibomian gland

Explain the process of tear production and drainage by the lacrimal apparatus.

• Tears are produced by the lacrimal gland and drained through the lacrimal ducts into the nasal cavity.

• Tears are produced by the salivary gland and drained through the ear canal.

• Tears are produced by the liver and drained through the small intestine.

• Tears are produced by the skin and drained through the sweat glands.

What are the main components of the lacrimal apparatus?

• lacrimal gland, lacrimal ducts, and the nasolacrimal duct

• conjunctiva, cornea, and iris

• tear duct, nasal cavity, and lacrimal bone

• eyebrow, eyelid, and eyelash

How does the lacrimal apparatus help in maintaining the health of the eyes?

• By creating a barrier that prevents tears from reaching the eyes.

• By producing and draining mucus to keep the eyes dry and dirty.

• By producing and draining tears to keep the eyes moist and clean.

• By causing dryness and irritation in the eyes.

What is the purpose of tears produced by the lacrimal apparatus?

• To make the eyes dry and irritated

• To protect the ears from infection

• To keep the eyes moist and protect them

• To cause blurry vision