Ear Flashcards
What is the name of the ear hole and it’s little flap?
External acoustic meatus and the tragus.
The external ear is surrounded by what tissue types?
Outer portion is cartilage and the inner part is bone.
What innervates the external acoustic meatus and what innervates the auricle?
What innervates the internal and external tympanic membrane?
V3 and CNX
Auricle: Lesser occipital nerve, great auricular nerve, V3 and CNX
External tympanic membrane - V3
Internal - glossopharyngeal
What are the boundaries of the middle ear?
Roof: the tegmental wall (nothing enters or exits)
Floor: the internal jugular vein runs under the floor.
The tympanic branch of the glossopharyngeal nerve runs into the middle ear through the floor and forms the tympanic plexus
Lateral wall (membranous wall): is the tympanic membrane and the epitympanic recess. Learn all the regions of the tympanic membrane.
Medial wall (labyrinthine wall): oval and round windows
Facial nerve goes through the facial canal and exits through the stylomastoid foramen. The facial nerve gives of the chorda tympani, which enters the posterior wall, runs behind the tympanic membrane and exits through the anterior wall.
Tympanic plexus
Promontory
Lesser petrosal nerve
Prominence of the lateral semilunar canal
Anterior wall: pharyngotympanic tube (eustation tube)
Tensor tympanic muscle,
corda tympani nerve
Carotidotympanic nerves (branch of the internal carotid plexus).
Posterior wall (mastoid wall): Stapedius tendon Corda tympani nerve
What is the name of the roof of the middle ear?
The tergmental wall - separates the ear from the middle cranial fossa.
What are the parts viable in the tympanic membrane?
Malleus: umbo, handle of malleus, lateral process of malleus, posterior malleolar fold, pars flaccida, anterior malleolar fold.
Cone of light: shiny bit at 5 o’clock. If you can’t see it, it may indicate infection.
What is the innervation of the tympanic membrane?
Outer surface: V3.
Inner surface: CNIX
What formaen does the facial nerve enter and exit the skull?
Enters through the internal acoustic meatus goes through the facial canal (in the middle ear) and exits through the styloimastoid foramen.
What nerve can you damage when using an otoscope?
The chorda tympani. The facial nerve gives of the chorda tympani, which enters the posterior wall, runs behind the tympanic membrane and exits through the anterior wall.
What are the contents of the middle ear?
Muscles, ossicles, chorda tympani and tympanic nerve plexus
What nerves does the tympanic plexus receive innervation from?
The tympanic branch of the glossopharyngeal nerve and branch from the internal carotid plexus (caroticotympanic nerve)
What can you damage by putting in otoscope too far?
Perforate the tympanic membrane and damaging the chorda tympani nereve resulting in loss of taste,
