Copyright © 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved.

SUFFIXES

 

 

• -acusis hearing
• -cusis hearing
• -meter instrument for measure
• -metry process of measurement
• -opia vision

Suffix Meaning

REVIEW SHEET

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Copyright © 2008, 2005 by Saunders, an imprint of Elsevier Inc. All rights reserved.

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Light and sound applied to the sense organs of the eye and ear activate receptors that send signals to the appropriate brain regions in the cortex where they are translated into images and sounds.

What types of receptors exist to process information about our environment?

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What are the parts of the eye labeled in the diagram?

What are the functions of the different parts of the eye?

See Vocabulary (pp. 674-676) for definitions of the parts of the eye and their functions.

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What are the parts of the eye labeled in the diagram?

What are the functions of the different parts of the eye?

See Vocabulary (pp. 674-676) for definitions of the parts of the eye and their functions.

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Why are corneal transplants often successful?

How many cones and rods are in the retina? (There are approximately 6.5 million cones and 120 million rods in the retina.)

There are three types of cones, each stimulated by one of the primary colors of light (red, blue, and green).

Which cones are most affected by color blindness? (either the red or green cones)

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Describe how light travels through the eye by following the pathways of the color coordinated tracts and visual fields.

What might happen if there are lesions in areas along the pathway leading to the right and left cerebral cortices?

Lesions of the cortical areas of the occipital lobe will likewise cause visual disturbance in the areas of the visual field where the information is normally interpreted by the brain.

See Figure 17-5 (p. 674) for pathway of light rays from cornea to cerebral cortex.

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CORRECT Answer is B, vitreous humor

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CORRECT Answer is C, blepharitis

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Do any of the students have any of these conditions? What are the causes?

How are these conditions corrected? (The following slide provides images of the errors and the correction.)

What is lens accommodation? (the refractory adjustment resulting when the muscles of the ciliary body produce flattening of the lens [for distant vision] and thickening and rounding [for close vision])

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The dashed lines in B and C indicate the contour and size of the normal eye.

What error of refraction is associated with presbyopia? (an inability to adjust the lens for accommodation to near vision)

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What is the surgical treatment for cataracts? How can vision be corrected in this process?

Surgical removal of the lens and implantation of an artificial lens behind the iris are treatments for cataracts.

If surgery isn’t possible, are there other treatments?

If an intraocular lens cannot be inserted, the patient may wear eyeglasses or contact lenses to help refraction.

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What is the treatment for this condition?

Chalazions often require incision and drainage.

Besides chalazion, what are some of the other eyelid abnormalities? See Table 17-1 Eyelid Abnormalities (p. 683)

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What is a treatment for diabetic retinopathy?

For severe hemorrhaging, laser photocoagulation and vitrectomy are helpful.

What is neovascularization?

An Internet search will lead to multiple sites focused on diabetes and vision.

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Discuss the many forms of glaucoma.

Do most people have glaucoma in one eye or both eyes? Why?

If a patient has glaucoma in one eye, what is the likely cause? What is the likely treatment?

What is tonometry?

Tonometry measures intraocular pressure to detect glaucoma.

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Discuss the location of the retina and macula.

Which form of macular degeneration (dry or wet) has a better prognosis and possible treatment?

Why is it important to treat strabismus in early childhood?

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What are the symptoms, causes, and treatments for retinal detachments?

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Ask students to name conditions that are diagnosed by the tests listed.

What type of eyedrop dilates the pupil? (mydriatic)

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How is the Snellen chart used?

How is the ratio that describes visual acuity interpreted?

Have students perform the visual acuity test on each other.

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Have students take the visual field test in class (noted in lesson plan).

Are students surprised by the results of the test? Why or why not?

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LASIK is an acronym for laser in situ keratomileusis (shaping of cornea).

Why can’t LASIK correct presbyopia?

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Keratoplasty: Also known as corneal transplant, the patient’s scarred or opaque cornea is replaced with a donor cornea.

Why does this procedure have such a high success rate compared to other transplants?

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In this procedure, the band pushes the two parts of the retina against each other to bring together the two layers of the detached retina.

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What sorts of conditions utilize these treatments?

Are they successful in curing both the symptoms and the cause?

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See Figures 17-20 (p. 689) and 17-21 (p. 690).

Name the three bones in the middle ear that move in response to vibrations of the tympanic membrane? (malleus, incus, stapes)

What is another name for the inner ear, and why is it referred to by this name? (It is called the labyrinth due to its circular, maze-like structure.)

What is the name of the bony, snail-shaped structure of the inner ear? (cochlea)

In addition to being the organ for hearing, what other important function is performed by the ear? (equilibrium)

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The external auditory meatus is lined with numerous cerumen glands which produce a waxy substance that lubricates and protects the ear.

Which part of the ear is most often pierced?

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How do these structures contribute to vibration?

Why are they susceptible to infection?

Why do conditions that affect the respiratory system also affect these structures?

The malleus, incus, and stapes make up the ossicles.

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The oval window separates the middle and inner ear.

The cochlea contains perilymph and endolymph through which vibrations travel.

The cochlea also contains the organ of Corti in which tiny hair cells receive vibrations from the auditory liquids and relay the sound waves to the auditory nerve fibers.

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The semicircular canals contain the saccule and utricle.

The canals contain endolymph and hair cells.

Fluid and hair cells fluctuate in response to movement of the head. This information is transmitted through nerve fibers to the brain.

The brain sends information to the body’s muscles to maintain equilibrium.

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CORRECT Answer is D, cochlea

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Why can surgery for acoustic neuroma lead to deafness and facial paralysis?

Nerve deafness (sensorineural hearing loss) results from impairment of the cochlea or auditory nerve.

What constitutes conductive deafness? (It results from impairment of the middle ear ossicles and membranes transmitting sound waves into the cochlea.)

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Why does fixation of the stapes bone cause deafness? What is the current therapy for this condition?

What is the current therapy for Ménière disease? How effective is the therapy?

Why do doctors put tubes in the ears?

What is the proper term for a surgical incision in the tympanic membrane and the insertion of a draining tube device?

Why does the anatomical structure of the Eustachian tube in children make them more susceptible to otitis media?

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Ask students to make some quick head movements and ask if any students are experiencing vertigo.

What sorts of situations induce vertigo (e.g., rides at amusement parks, ear infections, elevator rides, etc.)? Does the vertigo described in these situations stem from the wrong message being carried by the vestibular nerve or from movement of the fluids in the semicircular canals?

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How is audiometry performed?

See Figure 17-24 for an example of an audiometer.

With a cochlear implant, a small computer converts sound waves to electronic impulses that stimulate nerve fibers in ears.

What types of pathologies might require a cochlear implant for treatment?

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Obtain tuning forks and ask students to perform the Rinne and Weber tests on each other.

Obtain ear and oral thermometers. Ask students to compare their temperatures using both methods.

Is there a difference between the methods? If so, why?