15. The Special Senses

What is the difference between special senses and general senses?

Which of the following correctly matches the sense to the type of stimulus it measures in the environment?

Which of the following cranial nerves is not involved in the gustatory sense?

a. Vagus nerve (X)

b. Hypoglossal nerve (XII)

c. Facial nerve (VII)

d. Glossopharyngeal nerve (IX)

Tears normally flow from the lacrimal sac into the:

a. lacrimal gland.

b. lacrimal canaliculi.

c. lacrimal puncta.

d. nasolacrimal duct.

1. Match the cell type with the correct stimulus.     

____Rod or cone     

____Hair cell in cochlea     

____Gustatory cell     

____Olfactory neuron     

____Hair cell in vestibule

a. Head movement

b. Odorant

c. Photon

d. Taste substance

e. Sound wave

The axons of the olfactory nerve terminate in the:

a. olfactory epithelium.

b. olfactory bulb.

c. olfactory tract.

d. primary olfactory cortex.

Fill in the blanks: In an olfactory neuron, the binding of a(n) ______to its membrane receptor triggers a(n)_______potential in the axons of the______nerve.

The primary olfactory cortex is located in the:

a. frontal lobe.

b. occipital lobe.

c. parietal lobe.

d. temporal lobe.

Which of the following statements is true regarding gustatory cells?

a. They have microvilli that project into the taste pore.

b. There are only 10–20 gustatory cells in a typical taste bud.

c. They have a lifespan of approximately 6 months.

d. Some form synapses with neurons that give rise to the trigeminal nerve.

Match the taste with the chemical substance that produces it.      

____Sweet      

____Sour     

____Salty      

____Bitter      

____Umami

a. Many alkaloids

b. Sucrose

c. Glutamate

d. Sodium ions

e. Hydrogen ions

he axons from the nasal retina in the left eye terminate in the:

a. right lateral geniculate nucleus.

b. left lateral geniculate nucleus.

c. right medial occipital lobe.

d. left medial occipital lobe.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

a. The incus is connected to the tympanic membrane.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

b. The stapes is attached to the oval window.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

c. The auditory canal is separated from the middle ear by the round window.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

e. The semicircular ducts are connected to the utricle, and the cochlear duct is continuous with the saccule.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

d. The cochlear duct is filled with perilymph.

Mark the following statements as true or false. If a statement is false, correct it to make a true statement.

f. The spiral organ is located in the scala tympani.

Explain how sounds of different frequencies are detected in the cochlea.

How do the hair cells of the crista ampullaris detect rotation of the head?

The macula in the utricle detects:

a. rotation of the head to the right.

b. very low-frequency sound waves that we can feel but not hear.

c. tilting of the head to one side.

d. linear acceleration of the head in a vertical plane.

Fill in the blanks: The spiral organ sits on the________membrane, and the stereocilia of the outer hair cells contact the _____membrane.

True or false: Hair cells in the spiral organ will depolarize or hyperpolarize, depending on the direction in which the stereocilia are bent.

Which of the following is not part of the auditory pathway in the CNS?

a. Superior temporal lobe

b. Superior colliculus

c. Medial geniculate nucleus

d. Nuclei in the pons

e. Cochlear nuclei

Fill in the blanks: In the ampulla of a semicircular duct, the hair cells are located in the_____and their stereocilia and kinocilium are embedded in the______.

Stimuli from the inner ear regarding head movement and position are sent to all of the following except the:

a. vestibular nuclei.

b. oculomotor nucleus.

c. parietal lobe.

d. cerebellum.

e. trigeminal nucleus.

Explain what would happen to your sense of smell if there were no basal cells present in the olfactory epithelium.

In which direction would you be unable to move your right eye if your right abducens nerve were damaged?

Following a stroke, a patient lost vision in the left visual field. Name several structures in the brain that could have been damaged by the stroke to have caused this vision loss. Be specific as to right or left side.

Why do you have the sensation that you are still spinning immediately after stopping?

Mr. Spencer suffers loss of taste sensation. Tests reveal that his taste buds and salivary glands are functional. What other structures might be impaired that would explain his loss of taste?

If severe congestion from a cold prevented your pharyngotympanic tube from opening, what could happen to your tympanic membrane? Explain your answer.

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?