<prompt> The distance between tympanic membrane and medial wall of middle ear at the level of centre is:3 mm4 mm6 mm2 mm  <response>: d 2mmRef. BD Chaurasia, Human Anatomy 6th ed., Vol 3, page 277Part of the middle ear cavityDistance from lateral to medial wallEpitympanum6mm widestMesotympanum centre2mm narrowestHypotympanum4mm 