Anatomy of the ear Flashcards
Which part of the ear collects air vibration?
Auricle ( in the external ear )
What is the nerve supply of the auricle?
The facial nerve
Which part of the ear conducts sound waves from the auricle to the tympanic membrane?
External auditory meatus
What is the sensory nerve supply of the external auditory meatus?
Auriculotemporal nerve + Auricular branch of the vagus nerve
What is the nerve supply of the auricle?
The facial nerve
Which part of the ear conducts sound waves from the auricle to the tympanic membrane?
External auditory meatus
What is the lymph drainage of the external ear?
Superficial parotid, mastoid, and superficial cervical lymph nodes.
What is the air conducting cavity in the petrous part of temporal bone?
Middle ear ( tympanic cavity )
Transmit the vibration from the tympanic membrane ( eardrum) to the perilymph of the internal ear.
Auditory ossicles ( in the middle ear )
Separating the tympanic cavity from the meninges and the temporal lobe of the brain, and forms the roof of the middle ear.
Tegmen tympani bone
What is the impotence of the floor of the middle ear?
Separating the tympanic cavity from the superior bulb of the IJV
What are the two openings of the anterior wall of the middle ear?
Lower and larger: for auditory tube
Upper and smaller: for tensor tympani muscle
In which wall of the middle ear emerges the tendon of the stapedius muscle?
The posterior wall through the pyramid
On reaching the posterior wall of the middle ear, it curves downwards behind the pyramid.
Prominence of the facial nerve canal.
Triangular area in the tympanic membrane that is bounded by the malleolar folds.
Pars flaccida
What is the nerve supply of the tympanic membrane?
Auriculotemporal + auricular branch of the vagus nerve
What articulates with the long process of incus?
The head of stapes
What is the insertion of the stapedius muscle?
The neck of the stapes
What attaches the base of the stapes to the fenestra vestibuli?
Anular ligament
What is the nerve supply of the tensor tympani muscle?
Mandibular nerve ( branch of trigeminal nerve )
What is the nerve supply of the stapedius muscle?
The facial nerve
What are the muscles of the ossicles?
Tensor tympani + Stapedius
What connects the anterior wall of the tympanic membrane to the nasal pharynx?
The auditory tube
It serves to equalize air pressure in the tympanic cavity and the nasal pharynx.
The auditory tube
It communicates with the middle ear by the aditus.
The mastoid antrum
Describe the relations of the mastoid antrum?
Anterior wall: middle ear + auditus to the mastoid antrum.
Posterior wall: separates the antrum from the sigmoid veinous sinus + the cerebellum.
Lateral wall: forms the floor of the suprameatal triangle.
Medial wall: posterior semicircular canal.
Superior wall: tegmen tympani.
Inferior wall: mastoid air cell ( perforated ).
Continuous above with the mastoid antrum and the middle ear.
Mastoid air cells
Descend in the posterior wall of the middle ear, behind the pyramid, and finally emerges through the stylomastoid foramen into the neck.
The facial nerve
Preganglionic fibers of the greater petrosal nerve
Zygomatic and lacrimal nerves
Postganglionic fibers of the greater petrosal nerve.
Nasal and palatine nerves
Eventually joined by the deep petrosal nerve from the sympathetic plexus on the internal carotid artery and form the nerve of the pterygoid canal.
The greater petrosal nerve ( from the facial nerve )
It supplies the muscle within the pyramid.
Nerve to the stapedius
Arises from the facial nerve just above the stylomastoid foramen.
The chorda tympani
Crosses the root of the handle of the malleus.
The Chorda tympani
This nerve leaves the middle ear through the petrotympanic fissure and enters the infratemporal fossa, where it joins the lingual nerve.
The chorda tympani
Arises from the glossopharyngeal nerve, just below the jugular foramen.
The tympanic nerve
What is the nerve supply of the lining of the middle ear?
The tympanic plexus
Sends secretomotor fibers to the parotid gland.
The lesser petrosal nerve ( from the tympanic plexus )
The central part of the bony labyrinth.
The vestibule
Part of the vestibule, closed by the secondary tympanic membrane.
The fenestra cochleae
A semicircular canal, lies in the medial wall of the aditus, above the facial nerve.
The lateral semicircular canal
Divides the cochlear canal into the scala vestibuli above and the scala tympani below.
The basilar membrane
