The<unk>  portion of the<unk>  bone or pyramid is pyramidal and is wedged in at the base of the skull between the sphenoid and occipital. Directed medialward, forward, and a little upward, it presents for examination a base, an apex, three surfaces, and three angles, and contains, in its interior, the essential<unk> s of the organ of hearing.
Petrous part of the temporal bone
Orbital part of frontal bone
Alveolar process of maxilla
Orbital lamina of ethmoid bone
Frontal bone
Occipital bone
Spine of sphenoid bone
Sphenoid bone