Petrous apex

Changed by Derek Smith, 7 Feb 2022

Updates to Article Attributes

Body was changed:

Show markup changes

The petrous apex is the pyramid-shaped anteromedial part of the petrous part of the temporal bone. It is orientated obliquely in the skull base and articulates with the posterior aspect of the greater wing of the sphenoid and occipital bones.

The lateral boundary is the inner ear, medially the petro-occipital fissure, anteriorly the petrosphenoidal fissure and petrous part of the internal carotid artery in the carotid canal and posteriorly the posterior cranial fossa. Superiorly is the middle cranial fossa, Meckel cave and petrous ICA. Inferiorly is the jugular bulb and inferior petrosal sinus.

The internal auditory canal divides it into a larger anterior portion, containing bone marrow that may be pneumatised and a smaller posterior portion, derived from the otic capsule.

Anatomical variants

~~pneumatization~~pneumatisation of thepetrous apex

Related pathology

-<p>The <strong>petrous apex</strong> is the pyramid-shaped anteromedial part of the <a href="/articles/petrous-part-of-temporal-bone">petrous part of the temporal bone</a>. It is orientated obliquely in the skull base and articulates with the posterior aspect of the <a href="/articles/greater-wing-of-sphenoid">greater wing</a> of the <a href="/articles/sphenoid-bone">sphenoid</a> and <a href="/articles/occipital-bone">occipital bones</a>.</p><p>The lateral boundary is the <a href="/articles/inner-ear">inner ear</a>, medially the <a href="/articles/petro-occipital-fissure-1">petro-occipital fissure</a>, anteriorly the <a href="/articles/sphenopetrosal-suture">petrosphenoidal fissure</a> and petrous part of the <a href="/articles/internal-carotid-artery-1">internal carotid artery</a> in the <a href="/articles/carotid-canal">carotid canal</a> and posteriorly the <a href="/articles/posterior-cranial-fossa">posterior cranial fossa</a>. Superiorly is the <a href="/articles/middle-cranial-fossa">middle cranial fossa</a>, <a href="/articles/meckel-cave-1">Meckel cave</a> and petrous ICA. Inferiorly is the <a href="/articles/jugular-bulb">jugular bulb</a> and <a href="/articles/inferior-petrosal-sinus">inferior petrosal sinus</a>.</p><p>The <a href="/articles/internal-acoustic-canal">internal auditory canal</a> divides it into a larger anterior portion, containing bone marrow that may be pneumatised and a smaller posterior portion, derived from the <a href="/articles/otic-capsule">otic capsule</a>.</p><h4>Anatomical variants </h4><ul><li>pneumatization of the<strong> </strong>petrous apex</li></ul><h4>Related pathology</h4><ul>
~~-<li><a href="/articles/petrous-apex-cephalocoele">Petrous apex cephalocoele</a></li>~~
~~-<li><a href="/articles/asymmetric-fatty-bone-marrow-of-the-petrous-apex-1">Asymmetric fatty bone marrow of the petrous apex</a></li>~~
~~-<li><a href="/articles/cholesterol-granuloma">Cholesterol granuloma</a></li>~~
~~-<li><a href="/articles/petrous-apicitis">Petrous apicitis</a></li>~~
~~-</ul><h4>See also</h4><ul><li><a href="/articles/petrous-apex-lesions-differential">Petrous apex lesions (differential)</a></li></ul>~~
+<p>The <strong>petrous apex</strong> is the pyramid-shaped anteromedial part of the <a href="/articles/petrous-part-of-temporal-bone">petrous part of the temporal bone</a>. It is orientated obliquely in the skull base and articulates with the posterior aspect of the <a href="/articles/greater-wing-of-sphenoid">greater wing</a> of the <a href="/articles/sphenoid-bone">sphenoid</a> and <a href="/articles/occipital-bone">occipital bones</a>.</p><p>The lateral boundary is the <a href="/articles/inner-ear">inner ear</a>, medially the <a href="/articles/petro-occipital-fissure-1">petro-occipital fissure</a>, anteriorly the <a href="/articles/sphenopetrosal-suture">petrosphenoidal fissure</a> and petrous part of the <a href="/articles/internal-carotid-artery-1">internal carotid artery</a> in the <a href="/articles/carotid-canal">carotid canal</a> and posteriorly the <a href="/articles/posterior-cranial-fossa">posterior cranial fossa</a>. Superiorly is the <a href="/articles/middle-cranial-fossa">middle cranial fossa</a>, <a href="/articles/meckel-cave-1">Meckel cave</a> and petrous ICA. Inferiorly is the <a href="/articles/jugular-bulb">jugular bulb</a> and <a href="/articles/inferior-petrosal-sinus">inferior petrosal sinus</a>.</p><p>The <a href="/articles/internal-acoustic-canal">internal auditory canal</a> divides it into a larger anterior portion, containing bone marrow that may be pneumatised and a smaller posterior portion, derived from the <a href="/articles/otic-capsule">otic capsule</a>.</p><h4>Anatomical variants </h4><ul><li>pneumatisation of the<strong> </strong>petrous apex</li></ul><h4>Related pathology</h4><ul>
+<li><a href="/articles/petrous-apex-cephalocoele">petrous apex cephalocoele</a></li>
+<li><a href="/articles/asymmetric-fatty-bone-marrow-of-the-petrous-apex-1">asymmetric fatty bone marrow of the petrous apex</a></li>
+<li><a href="/articles/cholesterol-granuloma">cholesterol granuloma</a></li>
+<li><a href="/articles/petrous-apicitis">petrous apicitis</a></li>
+</ul><h4>See also</h4><ul><li><a href="/articles/petrous-apex-lesions-differential">petrous apex lesions (differential)</a></li></ul>