ANATOMY OF MIDDLE EAR скачать в хорошем качестве

ANATOMY OF MIDDLE EAR

The middle ear is a rectangular air-filled compartment in the temporal bone. MIDDLE EAR BOUNDRIES middle ear cleft ME + eustachian tube + mastoid walls of middle ear anterior wall 2 opening : 1. tensor tympani 2. eustachian tube eustachian tube also called as auditory tube/ pharyngotympanic tube connect pharynx to middle ear develop from first pouch length = 36 mm Isthmus = narrowest part of ET function maintain middle ear pressure drains the secretion of Middle ear medial wall two Windows : 1 oval window / fenestra vestibuli 2 round window / fenestra cochlea oval window is covered by foot plate of stapes round window is covered by secondary tympanic membrane process cochleariformis tensor tympani hook around process cochleariformis and comes out and attached to handle of malleus dome of lateral semicircular canal m /c site for labyrinthine fistula promontor outward bulge d/t first basal turn of cochlea posterior wall pyramid --- from is arises stapedius , smallest muscle in the body mastoid segment of facial nerve chorda tympani chord in Middle ear and exit from anterior wall by Canal of HUGIERUR facial recess : boundaries media -- facial nerve interior -- chorda facial angle lateral - chorda tympani superior -- short process of incus significance : site for posterior tympanotomy sinus tympani lateral - facial nerve posterior - posterior wall medial -- medial wall most common site for recurrent cholesteatoma lateral wall tympanic membrane scutum ,lasser extent divide middle ear into three parts 1. above tm --- epitympanum 2. in front tm --- Misotympanum 3. below tm -- hypotympanum