Ear Flashcards
What is the skin of the concha innervated by?
VII, IX, and X
What is the blood supply to the pinna?
superficial temporal a and posterior auricular a
What can trauma to the pinna cause in the subcutaneous tissue?
hemorrhaging
auricular hematoma
cauliflower ear?
What are the 3 layers of the tympanic membrane ?
skin, pars tensa (majority) / pars faccida, and inner mucous membrane
What innervates the layers of the tympanic membrane?
skin - GSA V, X
inner mucous membrane - GVA IX via tympanic plexus
What is the path of the chorda tympani in the ear?
runs through anterior and posterior mallear folds. crosses neck of malleus
What is otitis media?
occurs in infants and children.
accumulation of fluids and mucosa
Decreases hearing
happens in children bc auditory tubes are horizontal and impedes drainage
What can occur if there is a fracture of the petrous?
basilar skull fracture such as transverse or longitudinal fractures of temporal base can cause:
otorrhea, otorrhagia, and deafness
Bell’s palsy may result
some brain damage -> death
Describe the path of the facial n in the ear?
travels laterally in the internal auditory meatus before entering the facial canal
It turns sharply at the level of the geniculate ganglion = external genu
sends branch to stapedius m
exits sytlomastoid foramen
What is otosclerosis?
ossification or scarring of small ossicular joints
prevents transmission of sound
bone conduction test is NORMAL
nerve conduction test is ABNORMAL
Describe the tensor tympani m path, innervation and action
tendon loops laterally around processus cochleariformis and inserts into malleus
I: V3
Tightens and attenuates tympanic membrane vibrations
What is the action and innervation of stapedius m?
VII
Pulls stapes out of fenestra vestibuli protectiton mechanism
What is the sensory innervation of middle ear mucosal lining ?
GVA of IX via tympanic plexus
What is the innervation of the organ of corti?
VIIIc
What does the VIIIv innervate?
maculae utricle and saccule and cristae ampullaris
What is the processus cochleariformis?
bony pulley that the tendon of the tensor tymapni m loops before inserting on the manubrium of the malleus
What is the promontory ?
formed by basal turn of the cochlea and covered by the tympanic plexus (IX) and caroticotymapnic n
What artery in the ear can cause vertigo and nausea if there is atherosclerosis?
labryinthine a
br of AICA
What does the cochlear pass through?
Modiolus - bony core of cochlea
What does prolong exposure to excessive amounts of noise and music lead to?
partial destruction of the organ of corti
What is the innervation of the pinna?
GSA sensory by the auriculotemporal n (V3)
Lesser occipital and greater auricular n.
