Ear Flashcards
Describe the components of the Outer Ear
Auricle, external accoustic meatus/auditory canal, tympanic membrane
Describe the auditory canal
Lateral 1/3rd is cartilage and the medial 2/3rds is bone, there is also hairy skin with cerumen glands to prevent water mixing with skin
Describe the function of the tympanic membrane
It transmits vibrations from the EAM to the middle ear
Describe the anatomical features of the tympanic membrane
It is concave externally, has a cone of light in the antero-inferior quadrant (will shift in disease) and a handle of malleus
WHat are the the non boney features of the middle ear
Epitympanic recess to the mastoid air cells, auditory tube which connects to the nasopharynx, tympanic cavity proper and the Chorda tympani
Why are children more prone to Otitis Media
The Auditory canal is more horozontal and therefore predispososes bacteria to access the middle ear
What is the chorda tympani
Is a branch of the Facial nerve that has sensory capabilities for taste to the anterior 2/3rds of the tongue. Will exit at the internal acoustic meatus and then run over the tympanic membrane in between the malleus and incus. It will travel with the lingual nerve to the submadibular ganglion. Here will go on to innervate the submandibular and sublingual salivary glands.
What are the bones of the middle ear
From lateral to medial they are the malleus, incus and stapes
What muscles innervate the bones
Malleus by the Tensor Tympani (CNV2) and the stadedius muscle regulates the stapes
Function of the muscle of the inner ear
To prevent transmiting harmful vibrations to the inner ear
What is the imprint of the cochlear known as
Promontary
What are the features of the Inner ear
Oval window (sound conduction), round window (pressure release), petrous process of temporal bone
Difference between endolymph and perilymph
Endo is within the structures of the cochlear and vestibular whereas peri is between the bone and the structures of the cochlear and vestibular
What are the componants of the Vestibular system
Semicircular canals (Horozontal, posterior and anterior), ampulla (dynamic equilibrium) and the Utricle and Saccule (static equilibrium)
Regions of cochlear
Apex for low frequencies and base for high frequencies
