Base of skull. Inferior surface. (label for jugular foramen is at right, third from the bottom)
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The jugular foramen is a large foramen (opening) in the base of the skull, located behind the carotid canal. It is formed in front by the petrous portion of the temporal bone, and behind by the occipital bone; it is generally larger on the right than on the left side.
Cranial nerves IX (glossopharyngeal), X (vagus) and XI (accessory) and the inferior petrosal sinus and sigmoid sinus vein pass through the jugular foramen.
The jugular foramen may be subdivided into three compartments, each with their own contents.
- The anterior compartment transmits the inferior petrosal sinus
- The intermediate compartment transmits the glossopharyngeal, vagus and accessory nerves
- The posterior compartment transmits the sigmoid sinus (becoming the internal jugular vein) and some meningeal branches from the occipital and ascending pharyngeal arteries.
An alternative imaging based subclassification exists, delineated by the jugular spine which is a bony ridge partially separating the jugular foramen into two parts:
- The smaller, anteromedial, "pars nervosa" compartment contains CN IX, (tympanic nerve, a branch of CN IX), and receives the venous return from inferior petrosal sinus.
- The larger, posterolateral, "pars vascularis" compartment contains CN X, CN XI, Arnold's nerve (or the auricular branch of CN X involved in the Arnold's reflex, where external auditory meatus stimulation causes cough), jugular bulb, and posterior meningeal branch of ascending pharyngeal artery.
- Anatomy figure: 22:5b-12 at Human Anatomy Online, SUNY Downstate Medical Center
- Anatomy figure: 22:4a-08 at Human Anatomy Online, SUNY Downstate Medical Center
- cranialnerves at The Anatomy Lesson by Wesley Norman (Georgetown University) (IX, XI)
- "Anatomy diagram: 34257.000-1". Roche Lexicon - illustrated navigator. Elsevier. Archived from the original on 2012-07-22.