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Contents of Skull Canals, Foramina, and Fissures

Q: Which nerves pass through the jugular foramen?

The jugular foramen (foramen jugulare) transmits cranial nerves IX, X, and XI, along with the sigmoid sinus transitioning into the internal jugular vein.

Canales, foramina et fissurae cranii

For medical students2 min readUpdated 2026-10-10

The foramina, fissures, and bony canals of the skull serve as critical topographic pathways connecting the cranial cavity with other regions of the head and neck. These structures transmit major blood vessels, cranial nerves and their branches, as well as specific structures essential for the function of the brain and sensory organs.

Cranial nervesExit the cranial cavity through specialized foramina (e.g., CN VII–XII).

Meningeal vesselsSupply the meninges, passing through the foramen spinosum and foramen ovale.

Emissary veinsValveless veins located in the foramen caecum, parietal, mastoid, and condylar foramina.

Foramina of the Anterior and Middle Cranial Fossae

The anatomical structures of the anterior and middle cranial fossae act as conduits for nerves responsible for olfaction and facial innervation, as well as vessels supplying the meninges.

Foramen caecum: transmits an emissary vein providing venous outflow.
Cribriform foramina (foramina cribrosa): serve as the passage for olfactory nerve fibers (responsible for the sense of smell) and meningeal branches.
Foramen rotundum: contains exclusively neural structures, specifically the maxillary nerve ($V_2$).
Foramen ovale: transmits the mandibular nerve ($V_3$) out of the cranial cavity, along with an accessory meningeal artery branch.
Foramen spinosum: serves as the primary pathway for the middle meningeal artery, its accompanying veins, and a small meningeal branch of the mandibular nerve.
Foramen lacerum: transmits the greater and lesser petrosal nerves, as well as the glossopharyngeal nerve (CN IX).

Foramina and Canals of the Posterior Cranial Fossa and Temporal Bone

The posterior cranial fossa and temporal bone structures contain the largest and most functionally significant openings, transmitting the brainstem, organs of hearing and balance, and the caudal group of cranial nerves.

Jugular foramen (foramen jugulare): a major conduit transmitting three pairs of cranial nerves (CN IX, X, and XI) and venous structures.
Internal acoustic meatus (meatus acusticus internus): contains the facial (VII) and vestibulocochlear (VIII) nerves, along with labyrinthine arteries and veins supplying the inner ear.
Foramen magnum: the largest opening of the skull. It transmits the brainstem (medulla oblongata), along with associated arteries and nerves.
Hypoglossal canal (canalis hypoglossi): an isolated passageway for the hypoglossal nerve (CN XII).

Additionally, the temporal bone contains distinct canaliculus structures associated with the inner ear:

Cochlear canaliculus (canaliculus cochleae) and vestibular canaliculus (canaliculus vestibuli): transmit the perilymphatic and endolymphatic ducts, respectively.

Other Canals and Foramina

Beyond the major pathways, the cranial bones feature several specialized canals and foramina with localized functions.

Canals of the pterygopalatine ganglion: the palatovaginal (canalis palatovaginalis) and vomerovaginal (canalis vomerovaginalis) canals contain vessels and nerves related to the pterygopalatine ganglion.
Mandibular canal (canalis mandibulae): courses through the bone and houses the inferior alveolar nerve and matching blood vessels.
Emissary vein system: besides the foramen caecum, emissary veins are located in the mastoid (foramen mastoideum), parietal (foramen parietale), and condylar (foramen condylare) foramina.

Mnemonic

To remember the contents of the round (rotundum) and oval (ovale) foramina, use the mnemonic: "M(axillary) stands for Rotundum (Round); M(andibular) stands for Ovale".

Frequently asked questions

What passes through the foramen lacerum?

The foramen lacerum transmits the greater and lesser petrosal nerves, the glossopharyngeal nerve (CN IX), and emissary veins connecting the pterygoid plexus to the cavernous sinus. In life, the opening is filled with cartilage forming a synchondrosis.

What structures pass through the jugular foramen?

The jugular foramen transmits cranial nerves and venous structures ensuring innervation and venous drainage. Its contents include:

Glossopharyngeal nerve (CN IX).
Vagus nerve (CN X).
Accessory nerve (CN XI).
Sigmoid sinus (sinus sigmoideus) — transitions into the superior bulb of the internal jugular vein.

What anatomical structures pass through the foramen magnum?

The foramen magnum transmits the medulla oblongata, meninges, vertebral arteries, anterior and posterior spinal arteries, and the spinal roots of the accessory nerve.

What passes through the superior orbital fissure?

The superior orbital fissure transmits cranial nerves and blood vessels entering the orbit. Its contents include:

Oculomotor nerve (n. oculomotorius, CN III).
Trochlear nerve (n. trochlearis, CN IV).
Abducens nerve (n. abducens, CN VI).
Ophthalmic nerve (n. ophthalmicus, $V_1$).
Superior ophthalmic vein (v. ophthalmica superior).
Sympathetic fibers from the cavernous plexus.

What structures exit through the stylomastoid foramen?

The stylomastoid foramen transmits critical neurovascular structures exiting the cranial base, including:

Facial nerve (n. facialis, CN VII) — exiting the facial canal.
Stylomastoid artery and vein (a. et v. stylomastoidea).

What passes through the foramen ovale?

The foramen ovale transmits neural, arterial, and venous structures connecting the middle cranial fossa to the infratemporal fossa. Its contents include:

Mandibular nerve ($V_3$).
Accessory meningeal artery.
Emissary veins connecting the pterygoid plexus to the cavernous sinus.

Where are the emissary veins of the skull located?

Emissary veins pass through various foramina and canals of the skull bones, connecting extracranial veins to intracranial dural venous sinuses. They are found in:

Foramen caecum
Mastoid foramen (foramen mastoideum)
Parietal foramen (foramen parietale)
Condylar canal (canalis condylaris)
Foramen lacerum

What passes through the optic canal?

The optic canal transmits structures of the visual pathway and blood vessels entering the orbit. Its contents include:

Optic nerve (n. opticus, CN II).
Ophthalmic artery (a. ophthalmica).

What nerves and vessels does the mandibular canal contain?

The mandibular canal contains the inferior alveolar nerve, inferior alveolar artery, and corresponding veins.

Which nerves pass through the jugular foramen?

The jugular foramen (foramen jugulare) transmits cranial nerves IX, X, and XI, along with the sigmoid sinus transitioning into the internal jugular vein.

What structures are located within the foramen magnum?

The foramen magnum transmits the medulla oblongata, vertebral arteries, meninges, and spinal roots of the accessory nerve, connecting the cranial cavity with the vertebral canal.

Through which foramen does the middle meningeal artery enter?

The main trunk of the middle meningeal artery, accompanied by its veins and a branch of the mandibular nerve, passes through the foramen spinosum.

Where do the perilymphatic and endolymphatic ducts pass?

These inner ear structures pass through the cochlear canaliculus (canaliculus cochleae) and vestibular canaliculus (canaliculus vestibuli).

Go deeper

Topography and branches of the trigeminal nerve (CN V)
Course of the caudal group of cranial nerves (CN IX, X, XI, XII)
Blood supply to the dura mater
Structure and function of emissary veins
Anatomy of the inner ear (labyrinthine structures)