Ear Week 3 FINISHED

Question 1

What is the ear also known as?

Answer 1

The vestibulocochlear organ

Question 2

What are the 2 main functions of the ear?

Answer 2

Hearing

Equilibrium and balance

Question 3

What is the ear divided into

Answer 3

External
Middle
Inner

Question 4

Where are the structures relating to hearing and equilibrium located? How does the sound get there?

Answer 4

In the inner ear. The sound gets here by being transferred from the external and middle ear.

Question 5

What separates the middle and outer ear?

Answer 5

The tympanic membrane

Question 6

What joins the middle ear to the nasopharynx?

Answer 6

The pharygnotympanic tube

Question 7

What are the 2 parts of the outer ear?

Answer 7

Auricle and external auditory meatus

Question 8

What does the auricle do?

Answer 8

It aids in collecting sound

Question 9

What does the external auditory meatus do?

Answer 9

Conducts the sound to the tympanic membrane

Question 10

What does the auricle contain/what is it made of?

Answer 10

Mostly fibrocartilage covered in skin

Question 11

What are the depressions in the auricle called?

Answer 11

The concha

Question 12

What are the parts of the auricle? Explain each of the parts

Answer 12

The lobule - contains no cartilage, only fat, skin, connective tissue and vessels.
Tragus - projection of cartilage, anterior to EAM
Helix - outer curved fleshy ridge of the auricle
Scaphoid - boat shaped

Question 13

What bone does the EAM lead through?

Answer 13

The temporal bone

Question 14

How long is the EAM in adults?

Answer 14

2-3cm

Question 15

Describe the lateral 1/3 of the EAM:

Answer 15

Lateral 1/3 is cartilage, lined with skin and is continuous with the auricle

Question 16

Describe the medial 2/3 of the EAM:

Answer 16

The medial 2/3 is bone and lined with thin skin which is continuous with the tympanic membrane

Question 17

What is the name for ear wax?

Answer 17

Cerumen

Question 18

What is the function of cerumen?

Answer 18

Protects skin lining EAM
Water and insect repellant
Helps keep tympanic membrane pliable

Question 19

Where is cerumen made?

Answer 19

Ceruminous glands in the subcutaneous tissues of the cartilaginous part of the EAM produce cerumen

Question 20

What is the shape of the tympanic membrane?

Answer 20

Thin oval shaped, semitransparent membrane

1cm in diametre

Question 21

What covers the external surface of the tympanic membrane?

Answer 21

Very thin layer of skin

Question 22

What cover the inside of the tympanic membrane?

Answer 22

Internally covered by the mucous membrane of the middle ear

Question 23

How does the tympanic membrane transmit sound?

Answer 23

The tympanic membrane moves in response to air vibrations from the EAM

Movements are then transmitted through the ossicles to the inner ear

Question 24

Where is the middle ear found?

Answer 24

In the petrous part of the temporal bone

Question 25

What does the middle ear include?

Answer 25

The tympanic cavity | The epitympanic recess

Question 26

What are the contents of the middle ear?

Answer 26

Ossicles: the malleus, incus, stapes. Muscles: Stapedius and tensor tympani Chorda tympani nerve, a branch of the Facial nerve (CN VII) (provides taste fibres to the anterior 2/3 of the tongue, parasym to sublingual and submandibular glands Tympanic plexus of nerves (formed by Facial and Glossopharyngeal nerves)

Question 27

What do the ossicles do?

Answer 27

They form a chain across the tympanic cavity from the tympanic membrane to the oval window (which is the entrance to the middle ear)

Question 28

What are the ossicles covered with?

Answer 28

Mucous membrane but not periosteum

Question 29

Where does the tensor tympani arise?

Answer 29

Cartilaginous part of the pharyngotympanic tube Greater wing of the sphenoid bone Petrous part of the temporal bone

Question 30

Where does tensor tympani insert?

Answer 30

Malleus

Question 31

What is the function of tensor tympani and what is its nerve supply?

Answer 31

Dampens movements of the ossicles and tympanic membrane | Supplied by Mandibular nerve CN V (3)

Question 32

What is the claim to fame of the stapedius muscle?

Answer 32

Smallest voluntary striated muscle in the body

Question 33

Where does the stapedius arise?

Answer 33

Posterior wall tympanic cavity (temporal bone) | Stapes

Question 34

What is the function of the stapedius and what is its nerve supply?

Answer 34

Prevents excessive movement of the stapes | Supplied by Facial nerve CN VII (nerve to stapedius)

Question 35

What is the pharygnotympanic tube also known as?

Answer 35

The auditory tube or the eustachian tube

Question 36

Which part of the eustachian tube is bone>

Answer 36

Lateral/ posterior 1/3

Question 37

What is the eustachian tube made of excluding the bony part?

Answer 37

Cartilage

Question 38

What is the eustachian tube lined with?

Answer 38

A mucous membrane, which is continuous with the tympanic cavity and nasopharynx

Question 39

What is the function of the eustachian tube?

Answer 39

Equalises pressure in the middle ear with the atmospheric pressure

Question 40

When is the eustachian tube usually closed?

Answer 40

All the time except when eating, yawning, chewing, swallowing etc

Question 41

What opens the eustachian tube?

Answer 41

Levator veli palatini and tensor veli palatini (muscles of the soft palate)

Question 42

What is the mastoid antrum?

Answer 42

An air filled extension of the middle ear. It is a cavity in the mastoid process of the temporal bone

Question 43

What is in the floor of the mastoid antrum?

Answer 43

Has several apertures where it is continuous with the mastoid air cells

Question 44

What lines the mastoid antrum and why is it clinically significant?

Answer 44

A mucous membrane which is continuous with the lining of the middle ear

Question 45

What does the inner ear contain?

Answer 45

The vestibulocochlear organs

Question 46

What part of the inner ear/temporal bone are the vestibulocochlear organs found?

Answer 46

Found in the petrous part of the temporal bone

Question 47

What is the bony labyrinth?

Answer 47

A complex system of communicating cavities

Question 48

What is suspended within the bony labyrinth?

Answer 48

The membranous labyrinth

Question 49

What is the membranous labyrinth suspended within?

Answer 49

A fluid called the perilymph

Question 50

What does the membranous labyrinth contain?

Answer 50

Endolymph

Question 51

What are the fluids in the inner ear responsible for?

Answer 51

Involved in carrying sound wave to the end organs for hearing and balance

Question 52

What are the 3 parts of the labyrinth?

Answer 52

A cave composed of 3 parts: Cochlea Vestibule (saccule & utricle) Semicircular canals

Question 53

What is the cochlear?

Answer 53

Latin for small snail | Concerned with the reception of sound

Question 54

What is the vestibule?

Answer 54

Small oval chamber Contains the saccule and utricle Features the oval window on the lateral wall Part of the balancing apparatus

Question 55

What are the semicircular canals?

Answer 55

3 fluid filled bony loops | Part of the balance system

Question 56

What is the internal auditory meatus? How long is it and where is it located?

Answer 56

A narrow canal, about one centimetre long and is contained within the petrous part of the temporal bone.

Question 57

What is the IAM closed laterally by? What is it closed off from?

Answer 57

It is closed off from the internal ear by a thin perforated plate of bone

Question 58

What passes through the bony plate that separates the IAM from the internal ear?

Answer 58

The facial nerve, the vestibulocochlear nerve and some blood vessels.

Question 59

What happens to the vestibulocochlear nerve at the lateral end of the internal auditory meatus?

Answer 59

It divides into its 2 components to supply the various parts of the ear.