Chapter 15: Sense Organs

otitis media

middle ear infection

The retina is the incomplete innermost coat of the eyeball in that it has no anterior portion.

true

The retina is the innermost layer of the eye and contains structures called rods.

true

nyctalopia

"night blindness"

conjunctivitis

"pink-eye"

tinnitus

"ringing in the ear"

Deb is a woman with unusually poor vision. Without glasses, she needs to stand 20 feet away from an object to see it, whereas a person with normal vision to see that same object from 400 feet. How would you quantify her visual acuity? What must you score in a visual acuity exam after correction with glasses to avoid being designated as legally blind? With which type of refraction disorder is he inflicted? What shape lenses would be required to focus a clear image on her retina?

24/100; 22/100; myopia; the concave

trachoma

Chlamydial conjunctivitis

Kim became ill repeatedly with throat infections during her first few years of school. Lately, however, she has noticed that whenever she has a throat infection, her ears become very sore also. What might be the cause of this additional problem?

Eustachian tube connects the throat to the middle ear, providing a perfect pathway to an infection.

Which of the following structures is a disc-shaped nerve ending that is responsible for discerning light touch?

Merkel discs

In complete sentences, name the photopigments present and explain their role in vision.

The photopigment in rods is rhodopsin, which is highly-light sensitive. It allows us to see in very dim light by breaking down into opsin and retininal. The cones function to produce vision in bright light. There are three types with each having a different photopigment. Erythrolabes which breaks down in light rays in light colors. Chlorolabe breaks down in the presence of light rays in green colors. Cyanolabe breaks down in the presence in light rays in blue rays.

All of the following are primary taste sensations EXCEPT: a. sweet b. sour c. spicy d. bitter

c. spicy

astigmatism

an irregularity in the cornea

The external ear consists of the:

auricle and auditory canal

Which of the following about the sclera is true? a. It is a mucous membrane b. It is called the white of the eye. c. It lies behind the iris d. All of the above are true.

b. It is called the white of the eye.

Nerve impulses responsible for the sensation of taste are carried in all of the following cranial nerves EXCEPT: a. VII b. VIII c. IX d. X

b. VIII

Which of the following is NOT a proprioceptor? a. muscle spindle b. root hair plexus c. Golgi tendon receptor d. all of the above are proprioceptors

b. root hair plexus

Which of the following is NOT a general sense? a. touch b. taste c. temperature d. pain

b. taste

From superficial to deep, the three layers of tissue that compose the eyeball are:

c. sclera, choroid, retina.

Where are the taste sensations interpreted?

cerebral cortex

Olfactory receptors and taste buds are:

chemoreceptors

Mèniére disease

chronic inner ear disease characterized by progressive nerve deafness and vertigo

cataracts

cloudy spots in the eye's lens

The only structure of the inner ear concerned with hearing is the:

cochlear duct

The neuronal pathway of hearing begins at the:

cochlear nerve

The anterior portion of the sclera is called the:

cornea.

Dynamic equilibrium depends upon the functioning of the:

crista ampullaris

Which of the following statements about gustatory sense organs is true? a. They are called taste buds b. They are innervated by cranial nerves VII and IX c. They work together with the olfactory senses. d. All of the above are true

d. All of the above are true

Which of the following is NOT a true statement? a. Mechanoreceptors are activated by stimuli that "deform" the receptor. b. Taste and smell are examples of chemoreceptors. c. Photoreceptors respond to light stimuli. d. Thermoreceptors are activated by pressure.

d. Thermoreceptors are activated by pressure.

Olfactory epithelium consists of: a. epithelial support cells. b. basal cells c. cilia d. all of the above

d. all of the above

Accommodation the lens for near vision necessitates:

increased curvature of the lens.

glaucoma

excessive intraocular pressure caused by abnormal accumulation of aqueous humor

The passageway leading to the tympanic membrane is the:

external auditory meatus

A person with a 20/200 vision can see objects at a 100 feet that a person with normal vision can see at 20 feet.

false

A person with strabismus usually have double vision.

false

All of the muscles associated with the eye are smooth or involuntary.

false

Deficiency the blue-sensitive photopigments is the most common form of color blindness.

false

Glaucoma may result from a blockage of flow of vitreous humor.

false

Mechanoreceptors are activated by a change in temperature.

false

Somatic sense receptors located in muscles and joints are called visceroreceptors.

false

The canal of Schlemm drains the vitreous humor from the anterior chamber.

false

The correct order of the auditory ossicles from deep to the tympanic membrane is incus, malleus, and stapes.

false

The crista ampullaris is located in the nasal cavity.

false

The olfactory receptor cells lie in an excellent position functionally smell delicate odors.

false

The tip of the tongue reacts best to bitter taste.

false

Vertigo essentially means "fear of heights".

false

hyperopia

farsightedness

Which of the following is a structure of the middle ear?

incus

Proprioceptors:

function and relation to movements and body position.

The organ of Corti is the sense organ of what sense?

hearing

otosclerosis

inherited bone disorder that impairs conduction by causing structural irregularities in the stapes

Where are the specialized mechanoreceptors of hearing and balance located?

inner ear

An intrinsic eye muscle is the:

iris

Which two involuntary muscles make up the front part of the eye?

iris and ciliary muscle

People whose acuity is worse than 20/200 after correction are considered to be:

legally blind.

scotoma

loss of only the center of the visual field

The auditory tube connects the:

middle ear and the nasopharynx

myopia

nearsightedness

retinopathy

often caused by diabetes mellitus

An eye physician is a/an:

ophthalmologist.

All of the axons of ganglion neurons extend back to an area of the posterior eyeball called the:

optic disc

Which of the following are encapsulated nerve endings?

pacinian corpuscles

The neurons of the retina- in the order in which they conduct impulses- are:

photoreceptor neurons, bipolar neurons, ganglion neurons.

Which of the following spaces contains vitreous humor?

posterior cavity

presbycusis

progressive hearing loss associated with aging

The retina contains microscopic receptor cells called:

rods and cones.

The white of the eye is called the:

sclera.

The function of the lacrimal gland is to:

secrete tears.

vertigo

sensation of spinning

Conjunctivitis is a highly contagious infection.

true

Exteroceptors are often called cutaneous receptors because of their placement in the skin.

true

Free nerve endings are the simplest, most common, and most widely distributed sensory receptors.

true

Golgi tendon receptors are stimulated by excessive muscle contraction.

true

If the hairs of the organ of Corti are damaged, nerve deafness results- even if the vestibulocochlear nerve is healthy.

true

Light enters through the pupil and the size of the pupil is regulated by the iris.

true

Meissner's corpuscle is a tactile corpuscle.

true

Movement of the tympanic membrane from sound waves initiates vibration of the auditory ossicles.

true

Myopia occurs when images are focused in front of the retina rather than on it.

true

Olfaction requires the chemical response of a dissolved substance for a stimulus.

true

Refraction means "the deflection or bending of light rays".

true

The correct order of flow of tears is as follows: lacrimal glands, lacrimal duct, punctum, lacrimal canal, lacrimal sac, and nasolacrimal duct.

true

The macula provides information related to head position or acceleration.

true

The membranous labyrinth is filled with endolymph.

true

The olfactory receptors are chemical receptors.

true

The openings in separation of opsin and retina in the presence of light is called bleaching.

true

The transmission pathway for olfactory sensations is as follows: olfactory cilia, olfactory bulb, olfactory tract, thalamic, and olfactory centers of the brain.

true

The tympanic membrane separates the middle ear from the external ear.

true

With the condition of presbyopia the eye lens loses its elasticity.

true

The sense organ(s) responsible for the sense of balance is / are located in the:

vestibule