Anatomy of the ear

Question 1

Contents of the temporal bone of the skull?

Answer 1

Organs of hearing and balance

Facial (CN VII) and vestibulocochlear (CN VIII) nerves

Question 2

Structures passing through the internal acoustic meatus?

Answer 2

Facial and vestibulocochlear nerves

Labyrinthine artery + vein

Question 3

Functions of the facial nerve?

Answer 3

Motor:
muscles of facial expression, stapedius

Parasympathetic:
salivary and lacrimal glands

Special sensory:
taste in the anterior 2/3rds of the tongue

Somatic sensory: external ear

Question 4

Sensory innervation of the glossopharyngeal nerve?

Answer 4

Middle ear, Eustachian tube, nasopharynx, oropharynx and tonsils

Question 5

What causes mastoiditis?

Answer 5

Extension of middle ear infection into the mastoid antrum from the epitympanic recess, via the aditus ad antrum

Question 6

Contents of the inner ear?

Answer 6

The bony labyrinth filled with perilymph; the membranous labyrinth “floating” within the perilymph

Question 7

Inner ear contents responsible for vestibular sensation?

Answer 7

Semicircular ducts, utricle and saccule