Ear anatomy and physiology

Question 1

what is the name for the external ear?

Answer 1

auricle or pinna

Question 2

what is the auricle composed of?

Answer 2

skin
stratified keratinising squamous epithelium
elastic cartilage

Question 3

what is the external acoustic meatus composed of?

Answer 3

lateral 1/3 cartilage and skin

medial 2/3 bone and skin

Question 4

what is earwax produced by?

Answer 4

ceruminous and sebacious glands

Question 5

what are the 3 layers of the tympanic membrane?

Answer 5

outer squamous epithelial
middle fibrous connective tissue
inner columnar ciliated mucus membrane

Question 6

what can cause suppuration in the tympanic membrane?

Answer 6

perforation by trauma

Question 7

what are the 3 small bones in the ear called?

Answer 7

hammer - malleus
anvil - incus
stirrup - stapes

Question 8

what does the ossicular chain play a key role in?

Answer 8

sound conduction

Question 9

what happens if there is trauma to the ossicular chain?

Answer 9

chronic suppuration

bony sclerosis

Question 10

what tendon attaches to the stapes?

Answer 10

stapedius tendon

Question 11

what is the middle ear lined by?

Answer 11

columnar ciliated epithelium

Question 12

what does the middle ear contain?

Answer 12

ossicles
facial nerve
chorda tympani

Question 13

what is the middle ear connected to?

Answer 13

the mastoid system via aditus

post nasal space via eustachian tube

Question 14

what are the 2 parts of the tympanic cavity?

Answer 14

epitympanum

hypotympanum

Question 15

what are the dangers of infection/trauma to the facial nerve?

Answer 15

intracranial sepsis
facial nerve damage
deafness
dizziness

Question 16

where is the vestibulo located?

Answer 16

inner ear

Question 17

what is the purpose of the vestibulo?

Answer 17

cochlear organ (balance and hearing)

Question 18

what are the components of the bony labyrinth?

Answer 18

cochlea
vestibule
semi-circular canal

Question 19

what is the membranous labyrinth composed of?

Answer 19

sensory epithelium

Question 20

what are the 2 types of fluid in the inner ear?

Answer 20

perilymph

endolymph

Question 21

where does the internal auditory meatus join the brainsteam?

Answer 21

junction of pons and medulla

Question 22

what innervates the ear?

Answer 22

cervical nerve root branches
trigeminal nerve
glossopharyngeal nerve
vagus nerve
branches of the vestibulocochlear nerve

Question 23

what does the inner auditory meatus contain?

Answer 23

7th and 8th cranial nerves

Question 24

what is the clinical significance of the internal auditory meatus

Answer 24

site of aucostic neuroma and vestibular schwannoma

Question 25

what has the greatest effect on hearing loss?

Answer 25

loss of ossicular continuity (compared to perforation of the tympanic membrane)