Flashcards in Chapter 16: Ears Deck (11)
The 3 functions of the middle ear are:
-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.
The normal pathway of hearing is known as:
air conduction (AC)
-the most efficient
An alternate route of hearing is known as:
-bone conduction (BC)
-vibration of the bones of the skull is transmitted directly to the inner ear and to cranial nerve VIII.
The 3 types of hearing loss are:
-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.
The infant’s eustachian tube is __ then an adult's; therefore it is ____.
-shorter and wider
-easier for pathogens from the nasopharynx to move through the Eustachian tube to the middle ear.
In the child, the top of the pinna should match an imaginary line extending from the:
-Corner of the eye to the occiput.
-Also the ear should be positioned within 10 degrees of vertical
Otosclerosis is a common cause of:
-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.
-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
When using an otoscope for examination of an infant or child younger than age 3, pull the pinna:
-Straight down to match the slope of the ear canal
When using an otoscope for examination of an adult, pull the pinna:
-Up and back