Anterior part of jugular foramen

The endocranial entrance of the jugular foramen is divided into 2 compartments by the dural band:

• The smaller anterior part (pars nervosa) of jugular foramen

• The larger posterior part (pars venosa) of jugular foramen.

Although the glossopharyngeal nerve is located within the anterior part, the vagus and accessory nerves are located within the posterior part. Sometimes, there is a complete division of the foramen by a bony septum; partitions of the foramen vary in radiologic and anatomic studies. 

Although there is variability in partitioning of the endocranial jugular foramen, with an emphasis on its nerve contents, the cerebrospinal fluid (CSF) recess adjacent to the JF can be partitioned into 3 parts craniocaudally: the recess for the cochlear aqueduct, the recess for the glossopharyngeal nerve, and the recess for the vagus nerve and accessory nerve