Some emissary veins pass through the foramen lacerum.

Emissary veins (from the cavernous sinus to the pterygoid plexus)

Often, the emissary vein is encountered and this can be controlled with bipolar coagulation and/or bone wax.

Also, rupturing the emissary veins will result in a subdural hematoma which will compress the brain.

It is commonly stated that nothing passes through the foramen lacerum, but a more detailed look shows that emissary veins enter here.

Condylar emissary vein is a vein connecting the suboccipital plexus of veins with the sigmoid sinus.

Abnormal causes of asymmetry included invasion by nasopharyngeal melanoma, angiofibroma, carotid-cavernous fistula with drainage through the emissary veins, and neurofibromatosis.

The occipital emissary vein is a small emissary vein which passes through the condylar canal.

Breschet's veins: (venae diploici), Diploic veins connected with the cerebral sinuses by emissary veins.

There are also connections with the pterygoid plexus of veins via inferior ophthalmic vein, deep facial vein and emissary veins.

This foramen varies in size in different subjects, and is frequently impervious; when open, it transmits the emissary vein from the nose to the superior sagittal sinus.

The emissary veins are valveless veins which normally drain from the dural venous sinuses into veins that lie outside the skull (external veins).

It transmits a Mastoid emissary vein to the sigmoid sinus and a small branch of the occipital artery, the posterior meningeal artery to the dura mater.

Through the condylar canal, the occipital emissary vein connects to the venous system including the suboccipital venous plexus, occipital sinus and sigmoid sinus.

This layer is sometimes referred to as the "danger zone" because of the ease by which infectious agents can spread through it to emissary veins which then drain into the cranium.

Griesinger's sign: Erythema and edema over the mastoid process due to septic thrombosis of the mastoid emissary vein and thrombophlebitis of the sigmoid sinus.

One important emissary vein communicates from outside the skull through the sphenoidal emissary foramen inferior to the zygomatic arch with the cavernous sinus on the inside of the skull.

The veins of exit are to the superior and inferior petrosal sinuses as well as via the emissary veins through the foramina of the skull (mostly through foramen ovale).

The contents of this foramen neatly form the mnemonic 'OVALE' (otic ganglion, V, accessory meningeal artery, lesser petrosal nerve, emissary veins)

Occipital emissary vein There are also emissary veins passing through the foramen ovale, jugular foramen, foramen lacerum and hypoglossal canal.

The vacuum assist ruptures the emissary veins (connections between dural sinus and scalp veins) leading to accumulation of blood under the aponeurosis of the scalp muscle and superficial to the periosteum.

Around the foramen magnum they form an intricate network which opens into the vertebral veins and is connected above with the occipital sinus, the basilar plexus, the condyloid emissary vein, and the rete canalis hypoglossi.

They may be significant however, as it is possible for infection to spread via emissary veins from the pterygoid plexus to the cavernous sinus, which may result in cavernous sinus thrombosis, a rare but life-threatening condition.

Behind either condyle is a depression, the condyloid fossa, which receives the posterior margin of the superior facet of the atlas when the head is bent backward; the floor of this fossa is sometimes perforated by the condyloid canal, through which an emissary vein passes from the transverse sinus.

The parietal emissary vein connects it with the superior sagittal sinus; and as it passes across the mastoid portion of the temporal bone, it receives the mastoid emissary vein which connects it with the transverse sinus.