Protective Structures of the Eye

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Which structure provides a passage for lacrimal fluid from the lacrimal sac to the nasal cavity?

Meibomian glands

Ciliary glands

Nasolacrimal duct (correct)

Lacrimal canals

What is the function of the conjunctiva in the eye?

Producing tears

Secreting mucus (correct)

Producing antibodies

Protecting the eye

Where are the lacrimal glands located in relation to the eye?

Below the lateral end of the eye

Above the lateral end of the eye (correct)

Below the medial end of the eye

Above the medial end of the eye

What is the primary purpose of the lacrimal apparatus in the eye?

Protect, moisten, and lubricate the eye Signup and view all the answers

Which of the following structures produces an oily secretion to lubricate the eye?

Meibomian glands Signup and view all the answers

How many extrinsic or external eye muscles are responsible for eye movements according to the text?

6 Signup and view all the answers

What is the function of rhodopsin in the rods?

Absorb photons Signup and view all the answers

Why are cones activated by much brighter light compared to rods?

Cones require many more photons for activation Signup and view all the answers

What happens when photoreceptor proteins are activated by light?

They change shape Signup and view all the answers

Where does the signal go after reaching the inner end of rods and cones?

Sets of neural cells Signup and view all the answers

What is the role of charged ions in the cells during the visual signal process?

Initiate the action potential Signup and view all the answers

How does the optic nerve transmit visual information to the brain?

Through rhodopsin activation Signup and view all the answers

What is the outermost layer of the eyeball called?

Sclera Signup and view all the answers

Which eye structure allows for light to pass through and is the most exposed part of the eye?

Cornea Signup and view all the answers

What is the main function of the Iris in the eye?

Regulate amount of light entering the eye Signup and view all the answers

Which layer of the eye contains dark pigment to prevent light scattering inside?

Ciliary body Signup and view all the answers

In what conditions do the muscles of the eye contract to enlarge (dilate) the pupil?

Distant vision and dim light Signup and view all the answers

Which part of the eye acts like the diaphragm of a camera?

Pupil Signup and view all the answers

What is the function of the vitreous humor in the eye?

Helps keep the eyeball from collapsing inward Signup and view all the answers

Where is the canal of Schlemm located?

At the junction of the sclera and cornea Signup and view all the answers

What is the primary function of the aqueous humor?

Provides nutrients for the lens and cornea Signup and view all the answers

Which segment of the eye lasts a lifetime and is not replaced?

Posterior segment Signup and view all the answers

Why must the lens change its shape to focus on closer objects?

To ensure light is focused to a point on the retina Signup and view all the answers

What happens to the image formed on the retina as a result of the lens activity?

It is reversed from left to right, upside down, and smaller than the object Signup and view all the answers

What is the correct term for the condition where near objects appear clear, but objects farther away look blurry?

Myopia Signup and view all the answers

What causes hyperopia, or farsightedness?

Eyeball being too short Signup and view all the answers

In which condition are images focused as lines instead of points?

Astigmatism Signup and view all the answers

What is the visual acuity problem that results from the decreasing elasticity of the lens with aging?

Presbyopia Signup and view all the answers

Which type of corrective lenses are used to treat myopia?

Concave lenses Signup and view all the answers

What is the correct term for harmonious vision where images are correctly focused on the retina?

Emmetropia Signup and view all the answers