L8 T1 Auditory senses

Question 1

What are the bones that make up the auditory ossicles?

Answer 1

Malleus, Incus, and Stapes

Question 2

What bone attaches to the tympanic membrane?

Answer 2

Malleus

Question 3

What bone is the intermediate between the stapes and malleus?

Answer 3

incus

Question 4

What bone inserts onto the oval window?

Answer 4

stapes

Question 5

What structure does the oval window open to?

Answer 5

scala vestibuli

Question 6

What is the name for the membrane covered region at the end of the scala tympani?

Answer 6

round window

Question 7

Where does the tensor tympani insert?

Answer 7

on the malleus and pulls handle of malleus inward

Question 8

Where does the stapedius insert?

Answer 8

onto the stapes and pulls stapes outward

Question 9

What are the two muscles that reflexively contract in response to loud sounds in order to dampen the vibrations of the auditory ossicles?

Answer 9

Tensor tympani and stapedius

Question 10

What provides the impedance matching between the air and the fluid?

Answer 10

Tympanic membrane

Question 11

What structure of the ear consists of three side by side coiled tubes?

Answer 11

cochlea

Question 12

What are the major components of the cochlea?

Answer 12

Scala vestibuli, media, and tympani. As well as Reissner’s membrane.

Question 13

What does Reissner’s membrane separate?

Answer 13

Scala media from scala vestibuli

Question 14

What is one function of Reissner’s membrane?

Answer 14

maintains a special fluid within the scala media.

Question 15

The scala media and vestibuli are considered to be a single chamber as far as sound conduction is concerned. Why?

Answer 15

Because of the thinness of Reissner’s membrane.

Question 16

What structure separates scala media from scala tympani?

Answer 16

Basilar membrane

Question 17

What structure consists of 20k-30k fibers that project from the modiolus of the cochlea in which fibers can vibrate, and in which distal ends of the fibers are not fixed but embedded?

Answer 17

Basilar membrane

Question 18

The length of basilar fibers _________ from the oval window to the apex of the cochlea.

Answer 18

increases

Question 19

The diameter of basilar fibers __________ from the oval window to the apex of the cochlea.

Answer 19

decreases

Question 20

What structure generates nerve impulses in response to vibration to basilar membrane?

Answer 20

Organ of Corti

Question 21

What are the sensory receptors of the organ of corti?

Answer 21

Hair cells

Question 22

Hair cells stimulate what that lead to the spiral ganglion of Corti?

Answer 22

nerve fibers

Question 23

Stereocilia from the hair cells touch or are embedded in the overlying tectorial membrane. The bending of the hairs in one direction depolarizes them, and bending of them in the other direction causes _________.

Answer 23

Hyperpolarization.

Question 24

Neurons in the ganglion of Corti send axons via what nerve into the upper level of the medulla?

Answer 24

Cochlear nerve/CN VIII

Question 25

The movement of basilar fibers causes movement of what?

Answer 25

reticular lamina

Question 26

Movement of the reticular lamina causes shearing forces on the hair cells against what?

Answer 26

Tectorial membrane. Thus, whenever basilar membrane moves, hair cells become excited

Question 27

When hair cells move....

Answer 27

they become excited.

Question 28

The ______ is filled with endolymph

Answer 28

scala media

Question 29

The __________ and ________ are filled with perilymph

Answer 29

scala vestibuli and scala tympani

Question 30

What type of fluid contains a high concentration of potassium and low concentration of sodium?

Answer 30

endolymph

Question 31

What type of fluid contains a low concentration of potassium and a high concentration of sodium?

Answer 31

perilymph

Question 32

The tops of hair cells project through what structure and are bathed by endolymph?

Answer 32

reticular lamina

Question 33

Decibel is on what kind of scale?

Answer 33

logarithmic

Question 34

The +80 mV difference between endolymph and perilymph is given what name?

Answer 34

endocochlear potential

Question 35

The lower bodies of hair cells are surrounded by what fluid?

Answer 35

perilymph

Question 36

What is the Place Principle?

Answer 36

nervous system detects sound frequencies by determining positions along the basilar membrane that are most stimulated.

Question 37

What are the components of the auditory nervous system pathway?

Answer 37

- spiral organ of corti - dorsal and ventral cochlear nuclei - superior olivary nucleus - lateral lemniscus' nucleus - medial geniculate nucleus (thalamus) - auditory cortex