Chapter 16: Ears

Question 1

The 3 functions of the middle ear are:

Answer 1

• Conducts sound vibrations from the outer ear to the central hearing apparatus in the inner ear.
• Protects the inner ear by reducing the amplitude of loud sounds.
• Its eustachian tube allows equalization of air pressure on each side of the tympanic membrane in order to prevent membrane rupture.

Question 2

The normal pathway of hearing is known as:

Answer 2

air conduction (AC)
-the most efficient

Question 3

An alternate route of hearing is known as:

Answer 3

• bone conduction (BC)

- vibration of the bones of the skull is transmitted directly to the inner ear and to cranial nerve VIII.

Question 4

The 3 types of hearing loss are:

Answer 4

• Conductive hearing loss: involves a mechanical dysfunction of the external or middle ear and is considered a partial loss because the person is able to hear if the sound amplitude is increased enough to reach the nerve elements in the inner ear.
• Sensorineural (or perceptive) hearing loss: indicates pathology of the inner ear, cranial nerve VIII, or the auditory areas of the brain. A simple increase in amplitude may not enable the person to hear.
• Mixed loss: a combination of both types of hearing loss in the same ear.

Question 5

The infant’s eustachian tube is __ then an adult’s; therefore it is ____.

Answer 5

• shorter and wider

- easier for pathogens from the nasopharynx to move through the Eustachian tube to the middle ear.

Question 6

In the child, the top of the pinna should match an imaginary line extending from the:

Answer 6

• Corner of the eye to the occiput.

- Also the ear should be positioned within 10 degrees of vertical

Question 7

Otosclerosis is a common cause of:

Answer 7

• Conductive hearing loss in young adults between ages 20 and 40.
• It is a gradual hardening that causes the footplate of the stapes to become fixed in the oval window, thus impeding the transmission of sound.
• The result is progressive deafness.

Question 8

Presbycusis is

Answer 8

• A type of hearing loss that occurs with aging and is a gradual sensorineural loss caused by nerve degeneration in the inner ear or auditory nerve.
• Its onset usually occurs around age 50, and then slowly progresses

Question 9

When using an otoscope for examination of an infant or child younger than age 3, pull the pinna:

Answer 9

-Straight down to match the slope of the ear canal

Question 10

When using an otoscope for examination of an adult, pull the pinna:

Answer 10

-Up and back

Question 11

What color of the eardrum is a normal finding?

Answer 11

-pearly gray