The Ear Flashcards
label the outer ear
label the tympanic membrane seen using otoscopy
what type of joints are found between the ossicles?
synovial joints
which ossicle is in contact with the tympanic membrane?
malleus
which ossicle is in contact with the oval window?
stapes
name two muscles related to the ossicles?
- tensor tympani
- stapedius
what is the action of the tensor tympani?
pulls handle of malleus medially, tenses tympanic membrane
- reduces the amplitude of the tympanic membrane oscillations and thereby reduces sound transmission to the vestibular window.
what is the action of the stapedius muscle?
pulls stapes posteriorly to tighten the annular ligaments to reduce oscillation and prevents excessive movement of the stapes
name two areas with which the cavity of the middle ear communicates
- nasopharynx - communicates with the middle ear via the eustachian tube.
- mastoid air cells - communicated with the middle ear via the mastoid antrum and aditus.
within which part of the temporal bone do the middle and inner ear lie?
petrous part
the inner ear consists of a series of bone lined chambers called the?
bony labyrinth
inside the bony labyrinth lies a series of membranous chambers called the?
membranous labyrinth
what is the fluid that lies within the bony labyrinth called?
perilymph
what is the fluid that lies withing the membranous labyrinth called?
endolymph
what is the function of the cochlea and the semicircular canals?
cochlea plays a big role in hearing and semilunar canals are responsible for balance
label the ear
which structures compose the bony labyrinth?
cochlea
vestibule
three semi-circular canals
which structures compose the membranous labyrinth?
cochlear duct, semi-circular ducts, utricle and saccule
through which foramen does the facial nerve exit the posterior cranial fossa?
internal acoustic meatus
which nerves pass through the internal acoustic meatus
facial and vestibulocochlear
while in the middle ear cavity, what branch does the facial nerve give off?
chorda tympani
label
which nerve fibres does the chorda tympani transmit?
- parasympathetic (preganglionic) efferent fibres destined for submandibular and sublingual salivary glands. These are secretomotor.
- sensory fibres carrying the special sense of taste, supplying the anterior 2/3 of the tongue.
what is the innervation of the tensor tympani muscle?
mandibular branch of trigeminal nerve