Question 1

Which structure in the retina is responsible for the highest visual acuity, and why?

Accepted Answer

Fovea centralis, because it is densely packed with cones.

Question 2

During phototransduction, what is the sequence of events that leads to decreased neurotransmitter release in photoreceptors?

Accepted Answer

Light activates rhodopsin → Retinal changes shape → Activates transducin → Activates phosphodiesterase → $$\downarrow$$ cGMP → Na$$^+$$ channels close → Photoreceptor hyperpolarizes → $$\downarrow$$ glutamate release

Question 3

A patient presents with blurry vision and difficulty seeing distant objects. Examination reveals the image is focused in front of the retina. Which condition is this, and what lens corrects it?

Accepted Answer

Myopia; corrected with a concave lens.

Question 4

Which retinal cell type is responsible for generating action potentials that form the optic nerve?

Accepted Answer

Ganglion cells

Question 5

What is the primary function of lateral inhibition in the retina?

Accepted Answer

To improve visual sharpness by enhancing contrast at edges.

Question 6

Which of the following best describes the difference between rods and cones?

Accepted Answer

Cones are responsible for high acuity and color vision, and are concentrated in the fovea.

Question 7

A patient is diagnosed with glaucoma. What is the underlying cause and which structure is most affected?

Accepted Answer

Increased intraocular pressure; optic nerve is most affected.

Question 8

In the auditory pathway, which sequence correctly describes the transmission of sound from the external environment to the brain?

Accepted Answer

Auricle → Tympanic membrane → Ossicles → Oval window → Cochlea → Hair cells → Auditory nerve

Question 9

How is pitch (frequency) encoded in the cochlea?

Accepted Answer

By the location of vibration on the basilar membrane: base for high frequency, apex for low frequency.

Question 10

Which mechanism is responsible for the depolarization of hair cells in the cochlea?

Accepted Answer

Movement causes K$$^+ to $$enter the cell from endolymph.

Question 11

A patient with Ménière’s disease experiences dizziness due to excess endolymph. Which part of the vestibular system is primarily affected?

Accepted Answer

Semicircular canals

Question 12

Which structure in the vestibular system detects linear acceleration?

Accepted Answer

Utricle and saccule

Question 13

Which taste modality is detected by Na$$^+$$ channels?

Accepted Answer

Salty

Question 14

Which sense is unique in that its signals bypass the thalamus initially?

Accepted Answer

Smell (olfaction)

Question 15

A patient has sensorineural hearing loss. Which structure is most likely damaged?

Accepted Answer

Hair cells or auditory nerve

Question 16

Which of the following is a correct statement about the adaptation of taste?

Accepted Answer

Taste adapts rapidly, allowing quick adjustment to new flavors.

Question 17

Which of the following best explains the 'dark current' in photoreceptors?

Accepted Answer

Na$$^+$$ enters the cell in darkness, causing depolarization.

Question 18

Which mechanism is used by bitter, sweet, and umami taste receptors?

Accepted Answer

G-protein coupled receptors (GPCRs)

Question 19

Which structure contains otoliths and is involved in detecting head position relative to gravity?

Accepted Answer

Utricle and saccule

Question 20

A patient with cataracts has a cloudy lens. What is the most likely effect on vision?

Accepted Answer

Decreased visual acuity and blurry vision.

Special Senses: Vision, Hearing, Balance, Taste, and Smell – Study Guide

Study Guide - Practice Questions

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