Left medial view of petrous temporal bone. The internal auditory meatus is located on the posterior surface of the petrous bone. Medial to it is the petrooccipital fissure for the inferior petrosal sinus. The jugular foramen, a space between the petrous bone and occipital bone, is divided into two parts. The pars nervosa is the anteromedial portion of the jugular foramen and is smaller than the larger, posterolateral pars vascularis. It transmits the inferior petrosal sinus and glossopharyngeal nerve. The pars vascularis transmits the jugular bulb and the vagus and spinal accessory nerves. The hypoglossal canal is shown within the occipital bone and transmits the hypoglossal nerve. (Image courtesy of AL Rhoton, Jr.)