Jugular foramen !

The jugular foramen is an opening between the temporal and occipital bones; it carries cranial nerves IX, X and XI and drains blood into the jugular vein.

See in 3D →

Opens in the Durgical app, no sign-up needed.

What it is

An opening between the temporal and occipital bones.

What it does

Carries nerves IX, X and XI and drains the brain into the internal jugular vein.

Key facts

Where: Between the petrous temporal and occipital bones
Function: Transmits IX, X, XI, the internal jugular vein (from the sigmoid sinus) and inferior petrosal sinus

Relations

Contents: Glossopharyngeal (IX), vagus (X) and accessory (XI) nerves; the sigmoid sinus widening into the jugular bulb and internal jugular vein; the inferior petrosal sinus; meningeal branches of the ascending pharyngeal and occipital arteries
In front: Carotid canal, separated by a thin ridge of bone, where the internal carotid artery enters the skull
Medial: Hypoglossal canal, below and medial, with the hypoglossal nerve (XII); the occipital condyle
Lateral: Styloid process and stylomastoid foramen, where the facial nerve leaves the skull
Above: Floor of the middle ear (tympanic cavity) over the jugular bulb; the internal acoustic meatus above and in front
Behind: Groove of the sigmoid sinus, curving down to it from the transverse sinus

How to find it

It cannot be felt. From below, it is the large irregular opening between the petrous temporal and occipital bones, behind the carotid canal and medial to the styloid process. Inside the skull it lies at the lower end of the sigmoid sinus groove, in the posterior cranial fossa.

Examination

Gag reflex and palate: a weak gag on one side and the uvula pulled toward the healthy side point to IX and X
Voice and swallow: a breathy, hoarse voice from a paralysed vocal fold (X), confirmed by laryngoscopy
Shrug and head turn against resistance: a weak shrug on the same side and weak turning of the head away from it point to XI

On imaging

CT with bone windows shows its size and margins: a glomus tumour erodes them irregularly, a schwannoma widens them smoothly. MRI shows the salt-and-pepper look of larger paragangliomas; MR or CT venography separates slow flow in a large jugular bulb from thrombosis.

Clinical notes

High or dehiscent jugular bulb: the bulb rises into the floor of the middle ear, sometimes through a gap in the bone, and shows as a blue mass behind the eardrum; a hazard in ear surgery and not to be taken for a tumour
Causes of jugular foramen syndrome include paragangliomas, schwannomas, meningiomas, metastases, skull base fractures and infection
Clot can spread from the sigmoid sinus into the internal jugular vein after mastoid infection

Anatomical variants

The right foramen is usually larger than the left, because the right sinuses usually drain more blood
A bony bridge between its two edges can divide it into separate compartments

Test yourself

Think of the answer, then tap the question to see it.

Which nerves and veins pass through the jugular foramen?

The glossopharyngeal (IX), vagus (X) and accessory (XI) nerves; the sigmoid sinus becoming the internal jugular vein; the inferior petrosal sinus.

What are the signs of jugular foramen (Vernet) syndrome?

Weak gag, lost taste on the back of the tongue, hoarseness, swallowing trouble, uvula pulled to the healthy side and weak shrug (IX, X, XI).

How does a glomus jugulare tumour at the jugular foramen present?

Pulsatile tinnitus in time with the heartbeat, hearing loss and a red mass behind the eardrum, later palsies of the nerves in the foramen.

What does a blue mass behind the eardrum suggest near the jugular foramen?

A high or dehiscent jugular bulb; a hazard in ear surgery and not to be taken for a tumour.

Add to my cards (4)

Educational information, not medical advice. For any symptom, see a health professional.

Its names

Official Latin (TA2): foramen jugulare TA2 458
Official Spanish (DeCS): Agujero yugular
English (TA2): Jugular foramen

Sources: Terminologia Anatomica (TA2); Anatomy, Head and Neck: Jugular Foramen; Jugular Foramen Syndrome.

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Representative model, for educational purposes only.