Lecture 21: Special Senses 2

Question 1

Where Is Hearing & Equilibrium Information Sent To? (4)

Answer 1

Cortex,
Cerebrum,
Brainstem,
Cerebellum

Question 2

What Cranial Nerve Deals With Hearing & Equilibrium?

Answer 2

Cranial Nerve 8

Question 3

Middle Ear Consists Of?

Answer 3

Malleus,
Incus,
Stapes,
2 Muscles

Question 4

2 Muscles Of Middle Ear

Answer 4

Tensor Tympani Muscle,

Stapedius Muscle

Question 5

Tensor Tympani Muscle

Answer 5

Bones of skull to malleus

Question 6

Stapedius Muscle

Answer 6

Bones of skull to stapes

Question 7

Purpose Of Middle Ear Muscles

Answer 7

Help protect hearing during loud sounds,

Lowers amount of pressure/vibration that goes into the cochlea

Question 8

Process Of Sound Traveling Through Inner Ear

Answer 8

Sound waves vibrate tympanic membrane which transfers vibrations through ossicles to oval window and into cochlea in inner ear

Question 9

What In Inner Ear Made Up Of?

Answer 9

Bony labyrinth (cochlea, vestibule, semicircular canals)

Question 10

What Is Within The Bony Labyrinth?

Answer 10

Membranous labyrinth that is filled with endolymph (fluid)

Question 11

Cochlear Duct

Answer 11

Membranous labyrinth of the cochlea

Question 12

Where Is The Cochlear Duct?

Answer 12

Begins at oval window and spirals through the cochlea

Question 13

Spiral Organ (Organ Of Corti)

Answer 13

In the cochlear duct

Question 14

Stereocilia

Answer 14

Projections of hair cells in the spiral organ

Question 15

Where Do Spiral Organ Hair Cells Rest?

Answer 15

On top of basilar membrane

Question 16

What Membrane Lies Over The Top Of Hair Cells and Stereocilia In The Spiral Organ?

Answer 16

Tectorial Membrane

Question 17

Process Of Hearing

Answer 17

1. Sound waves vibrate tympanic membrane which transfers vibrations through ossicles to oval window and into cochlea in inner ear.
2. Pressure waves are created in perilymph surrounding the cochlear duct
3. Pressure waves cause distortion of basilar membrane
4. The causes stereocilia to contact the tectorial membrane
5. Causes depolarization of haircuts and branches of cn 8

Question 18

Where Is Information About Gravity And Acceleration/Deceleration Detected?

Answer 18

Vestibule

Question 19

Where Is Information About Rotational Movements Of The Head Detected?

Answer 19

Semicircular Canals

Question 20

Distortion Of Hair Cells In Ears Detects

Answer 20

Head rotation,

Pull of gravity

Question 21

What Is The Membranous Labyrinth Part Of The Vestibule Made Up Of?

Answer 21

Utricle and saccule

Question 22

What Are Hair Cells In Ear Grouped In?

Answer 22

Macule

Question 23

What Projects Into A Gel-Like Material In Ear?

Answer 23

Stereocilia

Question 24

Statoconia

Answer 24

Crystals sitting on top of the gel

Question 25

Otoliths

Answer 25

Group of statoconia

Question 26

When Head Is Tilted Or When We Accelerate, _______ & _______ Are Displaced

Answer 26

Otoliths,

Gel

Question 27

What Happens During Distortion Of Ear Hair Cells?

Answer 27

Movement distorts them and depolarizes them and the branches of CN 8

Question 28

Semicircular Canals

Answer 28

Membranous labyrinth extends through the 3 semicircular canals

Question 29

Ampulla

Answer 29

Base of each semicircular canal,

Widened area

Question 30

Crista

Answer 30

In each ampulla,

Contains hair cells

Question 31

Cupula

Answer 31

Gel-like structure that stereo cilia project into

Question 32

What Tells The Brain What Way Body Is Moving?

Answer 32

Fluid movement direction in ear

Question 33

Process Of Semicircular Canals

Answer 33

1. When head is rotated, endolymph in canals and ampullae moves
2. Endolymph movement causes movement of the cupula (gel) which displaces stereocilia
3. Displacement of stereocilia results in depolarization or hyper polarization of hair cell and branches of CN 8