Ear

Question 1

What are the 3 areas of the ear?

Answer 1

1. External ear
2. Middle ear
3. Internal ear

Question 2

What is another name for the middle ear?

Answer 2

Tympanic cavity

Question 3

What is another name for the internal ear?

Answer 3

Labyrinth

Question 4

What are the 3 areas of the external ear?

Answer 4

1. Auricle
2. External auditory meatus
3. Tympanic membrane

Question 5

What is the function of the auricle?

Answer 5

Assist in capturing sound waves into external acoustic meatus

Question 6

What type of gland produce ear wax?

Answer 6

Modified sweat gland called ceruminous gland

Question 7

What 2 tissues make up the external acoustic meatus?

Answer 7

1. Outer 1/3 is elastic cartilage

2. Inner 2/3 is bone

Question 8

What is the function of the external acoustic meatus?

Answer 8

Conduct sound waves towards tympanic membrane

Question 9

Describe the lining of the external acoustic meatus

Answer 9

Thin sin containing hair follicles, sebaceous glands and ceruminous glands

Question 10

What are the 3 layers of the tympanic membrane?

Answer 10

1. Outer - Cutaneous
2. Intermediate - Fibrous
3. Inner - Mucous

Question 11

Describe the circumference of the tympanic membrane

Answer 11

Has thickened fibrocartilaginous ring which is fixed to tympanic sulcus

Question 12

What bone is attached to the inner surface of the tympanic membrane?

Answer 12

Handle of the malleus

Question 13

What is found above the site of the handle of the malleus?

Answer 13

Anterior and posterior malleolar folds

Question 14

What is the area between the two malleolar folds called?

Answer 14

Pars flaccida

Question 15

What is found in the anteroinferior quadrant of the tympanic membrane?

Answer 15

Cone of light

Question 16

What is the function of the tympanic membrane?

Answer 16

Transmits sound vibrations of ossicles of middle ear

Question 17

What 2 things connects the middle ear to the nasopharynx?

Answer 17

1. Eustachian tube

2. Mastoid antrum

Question 18

What 3 bones are found in the middle ear?

Answer 18

1. Incus
2. Malleus
3. Stapes

Question 19

What 2 muscles are found in the middle ear?

Answer 19

1. Tensor tympani

2. Stapedius

Question 20

What is the function of the eustachian tube?

Answer 20

Allows air to enter middle ear to balance pressure and allow free movement of tympanic membrane

Question 21

What forms the roof of the middle ear?

Answer 21

Tegmen tympani of petrous temporal bone

Question 22

What forms the floor of the middle ear?

Answer 22

Plate of bone separating middle ear from internal jugular vein

Question 23

What 3 things are found forming the anterior wall of the middle ear?

Answer 23

1. Plate of bone which separates middle ear from internal carotid artery
2. Opening for eustachian tube
3. Canal for tensor tympani muscle

Question 24

What 3 things are found in the posterior wall of the middle ear?

Answer 24

1. Aditus to mastoid antrum
2. Pyramid containing stapedius
3. Posterior canaliculus for chorda tympani nerve

Question 25

What forms lateral wall of the middle ear?

Answer 25

Tympanic membrane

Question 26

What are 4 presenting features of the medial wall of the middle ear?

Answer 26

1. Facial canal 2. Promontory 3. Fenestra vestibuli 4. Fenestra cochleae

Question 27

What is the promontory found on the medial wall of the middle ear?

Answer 27

Rounded eminence formed by 1st turn of cochlea

Question 28

What is the fenestra vestibuli of the medial wall of the middle ear?

Answer 28

Opening above and behind promontory

Question 29

What is the function of the fenestra vestibuli of the medial wall of the middle ear?

Answer 29

Transmit vibrations of ossicles to perilymph in scala vestibuli

Question 30

What is the fenestra cochleae of the medial wall of the middle ear?

Answer 30

Opening below and behind the promontory closed by secondary tympanic membrane

Question 31

What is the innervation of the tensor tympani muscle?

Answer 31

Mandibular nerve of trigeminal

Question 32

What is the action of the tensor tympani muscle?

Answer 32

Dampens down vibrations of tympanic membrane

Question 33

What is the innervation of the stapedius muscle?

Answer 33

Facial nerve

Question 34

What is the action of the stapedius muscle?

Answer 34

Dampens down vibrations of stapes by pulling on neck of the bone

Question 35

What is the point in the stapedius?

Answer 35

Prevents excess movement of stapes helping to control amplitude in inner ear

Question 36

Describe the transmission of sound waves in the cochlea | 6 steps

Answer 36

1. Vibrations of stapes footplate at fenestra vestibuli create waves in perilymph of scala vestibuli 2. Waves move into scala tympani and dissipate at fenestra cochleae 3. Wave is transmitted to endolymph inside cochlear duct 4. Basilar membrane vibrates 5. Organ of Corti moves against tectoral membrane 6. Stimulates generation of nerve impulses to brain