THE SPECIAL SENSES

What is a tastant?

A substance dissolved in saliva that causes taste cells to depolarize.

Which of the following statements is true concerning substances that have a sour taste?

Both "Substances that taste sour have a low pH" and "Substance that taste sour have high concentrations of H⁺" are correct.

Suppose there was a drug that could dramatically decrease mucus secretion. Which of the following may be a side effect of this drug?

Decreased mucus secretion would also decrease a person's ability to smell due to less fluid associated with the olfactory organ.

Otoliths can break off and float inside the inner ear. What might happen if the otoliths settle on top of the hair cells?

Dizziness and inability to maintain balance may occur.

Damage to which of the following bones would most likely affect a person's olfactory perception?

Ethmoid

Nicholas is prone to sinus infections. Lately his mother has noticed he doesn't seem to hear her when she is standing behind him. Which of the following best explains Nicholas's condition?

Fluid associated with Nicholas's infection is inhibiting movement of the auditory ossicles, resulting in conductive hearing loss.

Absence of which of the following papillae would have the greatest effect on a person's sense of taste?

Foliate

Dr. Clark has been lecturing for 3 hours and her ears are beginning to "pop." Which of the following best explains her condition?

Inflammation of her pharynx is blocking airflow through her auditory tubes, resulting in uneven pressure across her tympanic membranes.

Which of the following situations would have the greatest effect on depth perception?

Losing one eye in an accident

Which of the following is not a condition that would be considered sensorineural hearing loss?

Loss of flexibility of the joint between the incus and the stapes

Damage to the left side of the brain near the visual cortex could result in which of the following visual changes?

Loss of right visual fields from both eyes

Lynn has an obstruction in her left lacrimal canaliculi. A result of this is that

Lynn appears to be constantly crying but only from her left eye.

Mary was involved in an accident that resulted in severe damage to several of her facial bones. As a result, her olfactory organ was damaged as well. Which of the following may be a side effect of her injury?

Mary will most likely notice a dramatic decrease in her ability to taste.

Matthew has taken a "mental health day" from work. At this moment, the level or neurotransmitter released by the photoreceptors in his eyes is at maximum. What is Matthew likely doing right now?

Matthew is sound asleep in a very dark room.

Rachel has a lesion on cranial nerve IX. Which of the following would you expect Rachel to experience?

Partial loss of the sense of taste

Sara is color blind. Her classmates don't believe her and say that color blindness can only occur in males. Which of the following would explain Sara's inheritance of color blindness best to her classmates?

Sara is homozygous recessive for color blindness, inheriting the mutant alleles from her father and her mother.

Which part of the eye is referred to in the statement "Don't fire until you see the whites of their eyes"?

Sclera

A 100 dB sound (loud) of 150 Hz (low pitch) would cause which of the following to occur?

The basilar membrane to vibrate vigorously near the apex.

When you travel in an elevator, what senses when the elevator is moving?

The hair cells of the otolithic membrane of the vestibule

You can smell the fragrance of your deodorant when you just put it on, but after a little while the smell fades. What explains this phenomenon?

The phasic nature of olfaction

Megan thinks she has a great new way to help her remember her anatomy notes. She wears a certain perfume only when she studies for the exam and the day of the exam. What is Megan attempting to stimulate in this exercise?

The secondary olfactory areas of the brain

Which of the following does not contribute to the sense of equilibrium?

Vallate papillae

Damage to the vestibular branch of the vestibulocochlear nerve would result in loss of_________.

balace

Humans are able to distinguish several million shades of color because

different proportions of cone cells respond to each wavelength of light.

Rapid changes in altitude can rupture the tympanic membrane. Symptoms that may occur include

hearing impairment.

Jessica is sitting in a cafe and excess lacrimal fluid is spilling over her lower palpebrae. This means that Jessica

is crying

Adjustment to close-range vision involves all of the following except

light adaptation.

Ricky's lenses are very round and his pupils are constricted. Ricky is most likely

reading a book.

Glaucoma is a state of elevated pressure within the eye that occurs when the_________ is obstructed so the aqueous humor is not reabsorbed as fast as it is secreted.

scleral venous sinus

When you spin while sitting in a swivel chair with your eyes closed, you can sense this movement by means of your_________.

semicircular ducts

If a physician applies eye drops that inhibit muscle fibers controlled by the parasympathetic division, you would expect

the patient's pupil to constrict.

A person who has damage to the basilar membrane nearest the oval window would likely not be able to hear

the tweeting of small birds.