15. The Special Senses

Suppose the round window in your middle ear became very stiff. What effect would this have on hearing, and why?

Mrs. Flores is a 45-year-old female who suffered a fracture of the ethmoid bone as the result of a car accident. Several days later, she complained that she couldn't taste her food very well. How is her injury related to the loss of taste sensation?

Your 60-year-old patient, Mr. Guster, has Bell's palsy, which causes dysfunction of those portions of the facial nerve that control muscles of facial expression. He is surprised when you tell him to tape the eyelids of his right eye closed at night to prevent dryness. Why might Bell's palsy cause dryness of the eye on the affected side?

Which of the following is not a possible cause of conduction deafness?

a. Impacted cerumen

b. Middle ear infection

c. Cochlear nerve degeneration

d. Otosclerosis

Olfactory nerve filaments are found

a. In the optic bulbs

b. Passing through the cribriform plate of the ethmoid bone

c. In the optic tracts

d. In the olfactory cortex

Where are the olfactory sensory neurons, and why is that site poorly suited for their job?

A progressive disorder characterized by the loss of higher-order cerebral functions is

(a) Parkinson's disease

(b) Parasomnia

(c) Huntington's disease

(d) Alzheimer's disease

A reduction in sensitivity in the presence of a constant stimulus is

(a) Transduction

(b) Sensory coding

(c) Line labeling

(d) Adaptation

Which of the following statements does not correctly describe the spiral organ?

a. Sounds of high frequency stimulate hair cells at the basal end.

b. The 'hairs' of the receptor cells are embedded in the tectorial membrane.

c. The basilar membrane acts as a resonator.

d. The more numerous outer hair cells are largely responsible for our perception of sound.

Pitch is to frequency of sound as loudness is to

a. Quality

b. Intensity

c. Overtones

d. All of these

Sound waves are converted into mechanical movements by the

(a) Auditory ossicles

(b) Cochlea

(c) Oval window

(d) Round window

(e) Tympanic membrane

The spiral organ is located in the_______of the internal ear.

(a) utricle

(b) bony labyrinth

(c) vestibule

(d) cochlea

Identify the structures of the external, middle, and internal ear in the following figure.

<IMAGE>

a. ___

b. ___

c. ___

d. ___

e. ___

f. ___

g. ___

h. ___

i. ___

Auditory information about the frequency and intensity of stimulation is relayed to the CNS over the cochlear nerve, a division of cranial nerve

(a) IV

(b) VI

(c) VIII

(d) X

Displacement of stereocilia toward the kinocilium of a hair cell

(a) Produces a depolarization of the membrane

(b) Produces a hyperpolarization of the membrane

(c) Decreases the membrane permeability to sodium ions

(d) Increases the membrane permeability to potassium ions

(e) Does not affect the membrane potential of the cell