The Ear

Question 1

How does Sound work?

Answer 1

Particles in ear vibrate due to changes in air pressure = sound waves
Mechanoreceptors - convert sound energy to electrochemical energy which the brain perceives as sound

Question 2

Sections of the Ear

Answer 2

Outer (gas)
Middle (solid)
Inner (liquid)

Question 3

Functions of the Ear

Answer 3

Hearing
Equilibrium (balance)

Question 4

What are Mechanoreceptors?

Answer 4

Tiny hairs located in the inner ear - pick up sensory information from sound waves, balance, position and generates the Action Potential in sensory neurons

Question 5

Outer Ear

Answer 5

Pinna (auricle)
Auditory Canal (2.5cm)

Question 6

Pinna (auricle) (Outer Ear)

Answer 6

Outside flap of the ear to enhance sound vibrations & focus them into the ear (skin & cartilage)

Question 7

Auditory Canal (2.5cm) (Outer Ear)

Answer 7

Tube that leads to ear drum and amplified sound waves. This is where there are hair and wax to prevent foreign material from getting into the ear

Question 8

Middle Ear (Air Filled) TOE

Answer 8

Tympanum
Ossicles
Eustachian Tube

Question 9

Tympanum (Middle Ear)

Answer 9

Eardrum; round, elastic structure that structure that vibrates in response to sound waves, They are passed on to Ossicles

Question 10

Ossicles (Middle Ear)

Answer 10

3 smallest bones in the body. Interconnected in the middle ear where sound is passed from one to the next (malleus/hammer -> incus/anvil -> stapes/stirrup) and then onto the oval window (a small membrane that transmits sound vibrations to the inner ear)
The strength of the vibration is amplified as it passes through each ossicle

Question 11

Eustachian Tube (Middle Ear)

Answer 11

Connects middle ear to throat; allows pressure to equalize when there is a difference in air pressure in the middle ear and outside (“popping” your ears)
Also an area where pathogens travel from nose, throat to ear

Question 12

Inner Ear SVCob

Answer 12

Semicircular Canals
Vestibule
Cochlea (coiled)
Organ of Corti
Basilar Membrane

Question 13

Semicircular Canals (Inner Ear)

Answer 13

Sensors for movement and balance

Question 14

Vestibule (Inner Ear)

Answer 14

Sensors for balance

Question 15

Cochlea (coiled) (Inner Ear)

Answer 15

Mechanical energy of sound converted into an electrochemical impulse to the brain
Organ of Corti - organ of hearing. Has microscopic hairs (stereocilia that float in fluid, which detect sound vibrations
When stereocilia bend, they create an Action Potential in sensory neurons that are in the auditory nerve
Basilar Membrane - base of the OoC, contains sensory Mechanoreceptors (hair cells) that’s stimulate the auditory
nerve (relays info. To the sensory cortex, temporal lobe for interpretation)

Question 16

Hearing Pathway

Answer 16

Pinna & Auditory canal of the outer ear collect sound waves
Sound waves create vibrations in the Tympatic Membrane that are conducted via the Ossciles to the oval window
Vibrations of the oval window on the surface of the cochlea create pressure waves in the cochlear fluid
As the Basilar Membrane vibrates, hair cells brush against the Tectorial Membrane. This stimulus causes the hair cells to DP and relapse an NT; creating an AP in a SN

Question 17

How does the Organ of Corti detect low and high frequencies?

Answer 17

Hair cells at the top of the Cochlea respond to lower frequencies, and hair cells at the base respond to higher frequencies

Question 18

Nerve Deafness

Answer 18

It happens because of damage to the auditory nerve, the brain or the inner ear

Question 19

Conduction Deafness

Answer 19

Occurs when sound is unable to get through the outer & middle ear

Question 20

The 3 Semicircular Canals’s role in balance

Answer 20

There is liquid inside each of them, and when your head moves, so does the liquid, which intern moves the hairs lining the canal. The hair tells your brain the liquid is moving through nerve messages. Then your brain tells the body how to stay balanced
They also play a major role in rotational equilibrium

Question 21

The role of the Utricle and Saccule in balance

Answer 21

Detect the up and down and side to side tilt respectively, using small stones and viscous fluid
The Otoliths (ear stones) are small granules in the inner ear used for gravitational equilibrium