Question 1

Which of the following correctly traces the path of lacrimal secretions from the lacrimal gland to the nasal cavity?

Accepted Answer

Lacrimal gland $$\rightarrow$$ lacrimal canaliculi $$\rightarrow$$ lacrimal sac $$\rightarrow$$ nasolacrimal duct $$\rightarrow$$ nasal cavity

Question 2

Which of the following best describes the three layers of the eyeball?

Accepted Answer

Fibrous tunic, vascular tunic, and neural tunic

Question 3

Which sequence correctly traces the flow of aqueous humor from its production to its drainage?

Accepted Answer

Ciliary processes $$\rightarrow$$ posterior chamber $$\rightarrow$$ pupil $$\rightarrow$$ anterior chamber $$\rightarrow$$ canal of Schlemm

Question 4

Which of the following best defines the focal point in the context of vision?

Accepted Answer

The point at which light rays converge after passing through the lens

Question 5

A patient is unable to accommodate their lens for near vision. Which structure is most likely malfunctioning?

Accepted Answer

Ciliary muscle

Question 6

What happens to the focal distance as an object moves closer to the eye?

Accepted Answer

The focal distance increases

Question 7

Which of the following best compares looking at a close object versus viewing a distant object?

Accepted Answer

For a close object, the ciliary muscle contracts, lens becomes more convex; for a distant object, the ciliary muscle relaxes, lens flattens

Question 8

A person has 20/20 vision in one eye and 20/25 vision in the other. What does this mean?

Accepted Answer

The 20/25 eye must be 20 feet away to see what a normal eye sees at 25 feet

Question 9

Which part of a rod or cone is responsible for phototransduction?

Accepted Answer

The outer segment

Question 10

Which of the following best describes the visible light spectrum?

Accepted Answer

Wavelengths from approximately $$400\ \mathrm{nm} to$$ $$700\ \mathrm{nm}$$

Question 11

A rod in the dark has a resting potential of $$-40\ \mathrm{mV}$$ instead of $$-70\ \mathrm{mV}. $$What causes this difference?

Accepted Answer

Open cGMP-gated Na$$^+$$ channels allow Na$$^+$$ influx, depolarizing the cell

Question 12

What happens to rhodopsin when it is bleached by light?

Accepted Answer

Retinal changes from 11-cis to all-trans form and dissociates from opsin

Question 13

Which of the following best describes the steps involved in activating proteins in photoreceptors?

Accepted Answer

Light activates rhodopsin $$\rightarrow$$ transducin $$\rightarrow$$ phosphodiesterase (PDE) $$\rightarrow$$ cGMP breakdown

Question 14

What happens to cGMP once PDE is activated in a photoreceptor cell?

Accepted Answer

cGMP is hydrolyzed to GMP, causing Na$$^+$$ channels to close

Question 15

After exposure to light, how is a rod hyperpolarized?

Accepted Answer

Na$$^+$$ channels close, reducing Na$$^+$$ influx and making the inside more negative

Question 16

Which of the following best compares light and dark adaptation in the eye?

Accepted Answer

Light adaptation involves rapid bleaching of photopigments; dark adaptation involves regeneration of photopigments

Question 17

How do humans see in color, and what are the major functions of rods and cones?

Accepted Answer

Cones detect color (red, green, blue); rods detect dim light and are more sensitive to movement

Question 18

Which of the following correctly traces the path of an action potential along the visual pathway?

Accepted Answer

Photoreceptor $$\rightarrow$$ bipolar cell $$\rightarrow$$ ganglion cell $$\rightarrow$$ optic nerve $$\rightarrow$$ optic chiasm $$\rightarrow$$ optic tract $$\rightarrow$$ lateral geniculate nucleus $$\rightarrow$$ visual cortex

Anatomy & Physiology of the Eye: Structure, Function, and Visual Pathways

Guida di studio - Domande di pratica

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