=====Spine of Henle=====
The inner end of the external acoustic meatus is closed, in the recent state, by the tympanic membrane; the upper limit of its outer orifice is formed by the posterior root of the zygomatic process, immediately below which there is sometimes seen a small spine, the suprameatal spine also called the spine of Henle, situated at the upper and posterior part of the orifice.

{{::mastoidectomy.jpg|}}

MAC: [[mastoid air cells]]; SH: [[spine of Henle]]; SMC: [[suprameatal crest]].