The Ear and Hearing

Question 1

What are the three parts of the ear?

Answer 1

Outer ear
Middle ear
Inner ear

Question 2

What are the three parts of the Outer ear?

Answer 2

Aurical / Pinna
External auditory meatus (ear canal)
Tympanum (ear drum)

Question 3

What is the role of Outer ear?

Answer 3

Converts acoustic energy into kinetic energy

Question 4

Why is the auricle and external auditory meatus shaped in a specific way?

Answer 4

To preferentially filter and amplify sounds for human speech

Question 5

What is the shape of External auditory meatus?

Answer 5

Sigmoidal shaped

Question 6

Describe what the External auditory meatus is surrounded by?

Answer 6

First 1/3rd of canal is surrounded by cartilage

Last 2/3rds of canal is surrounded by bone

Question 7

What is found in the Cartilaginous portion of the Eardrum?

Answer 7

Hair, sebaceous glands, cerumineous glands

Question 8

What structure separates the External ear from the Middle ear?

Answer 8

Tympanic membrane

Question 9

The Tympanic membrane is concave externally - what is the most depressed part of the cavity called?

Answer 9

Umbo

Question 10

Which bone is attached to the medial Tympanic surface?

Answer 10

Malleus

Question 11

The three bones of the Middle ear are called?

Answer 11

Ossicles

Question 12

What is the name of the three Ossicles in the ear? Lateral to medial

Answer 12

Malleus (hammer)
Incus (anvil)
Stapes (stirrup)

Question 13

What is the function of the Eustachian tube?

Answer 13

Pressure equalisation between the middle ear and external ear

Question 14

Where is the Eustachian tube located in the ear?

Answer 14

Middle ear

Question 15

What are the middle ear muscles? What do they attach to?

Answer 15

Tensor tympani: Attached to the Malleus

Stapedius: Attached to the Stapes

Question 16

What is the role of the Middle ear muscles?

Answer 16

Acoustic reflex against high intensity sounds

Question 17

What is the innervation of the Middle ear muscles?

Answer 17

Stapedius: Facial nerve

Tensor Tympani: Mandibular branch of Trigeminal

Question 18

Bone conducts what frequencies of sound compare to air conduction?

Answer 18

Bone conducts lower frequencies than via air conduction

Question 19

The inner ear comprises what two structures?

Answer 19

Cochlear (hearing) 
Vestibular system (balance)

Question 20

What are the three structures of the Cohlear?

Answer 20

• Scala media
• Scala vestibuli
• Scala tympanic

Question 21

What is the range of human hearing?

Answer 21

20 Hz to 20,000 Hz

Question 22

What is “Ultrasound” and “Infrasound”

Answer 22

Ultrasound: Beyond human hearing range

Infrasound: Below human hearing range

Question 23

What are the two types of Cillia on the Cochlear hair cells?

Answer 23

Sterocilla (short) and Kinocillium (long)

Question 24

Describe the path of the Auditory pathway (SLIM)

Answer 24

Superior Olivary Complex -> Lateral Lemniscus -> Inferior Colliculus -> Medial Geniculate Nucleus

Question 25

Where is the auditory cortex located in the brain?

Answer 25

Temporal lobe

Question 26

What are the two types of hearing loss?

Answer 26

Conductive hearing loss | Sensorineural hearing loss

Question 27

What is Conductive hearing loss?

Answer 27

Problems conducting sound waves through outer ear, eardrum or middle ear

Question 28

What is Sensorineural hearing loss?

Answer 28

Problems in the cochlea, vestibulocochlear nerve or auditory cortex of brain

Question 29

By performing the Rinne's test, and it is found that Air Conduction (AC) is better than Bone Conduction (BC) - what does this mean?

Answer 29

Either normal, or sensorineural deafness

Question 30

By performing the Rinne's test, and it is found that Bone Conduction (BC) is better than Air Conduction (BC) - what does this mean?

Answer 30

Conductive deafness

Question 31

I have performed a Rinne test which found AC > BC, after performing Weber's the patient said they sounded the noise louder on the right side - what is the diagnosis?

Answer 31

Left sensorineural deafness

Question 32

I have performed a Rinne test which found AC > BC, after performing Weber's the patient said they sounded the noise louder on the left side - what is the diagnosis?

Answer 32

Right sensorineural deafness