The "cone of light" is seen in which quadrant of tympanic membrane?
Ans. b (Anteroinferior). (Ref Diseases of Ear, Nose and Throat, 6th/pg. 71)Tympanic membrane:# It develops from all three germinal layers: ectoderm (outer epithelial layer), mesoderm (middle fibrous layer), and endoderm (inner mucosal layer).# The normal tympanic membrane is --pearly/shiny greyish white.# The area of tympanic membrane is 90 sq. mm. and of stapes 3.5 sq mm.# Out of 90 sq.mm area of the tympanic membrane, only 55 sq mm is functional.# Normal tympanic membrane is mobile and the concavity on its lateral surface is more marked.# At the tip of malleus--the umbo.# Cone of light is seen in--anteroinferior quadrant.# Attic area is pinkish & lies above lateral process of malleus.Q.Ans.Cone of lightAnteroinferior quadrantMyingotomyPosteroinferior QuadrantGrommet insertionAnteroinferior QuadrantDirection of waterjet during syringingPostero superior
Anterosuperior
Anteroinferior
Posterosuperior
Posteroinferior
Anatomy of External Ear & Pinna