The cavernous sinus within the human head is one of the dural venous sinuses creating a cavity called the lateral sellar compartment bordered by the

temporal bone The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. ...

of the

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, th ...

and the sphenoid bone, lateral to the

sella turcica The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalome ...

Structure

The cavernous sinus is one of the dural venous sinuses of the head. It is a network of veins that sit in a cavity. It sits on both sides of the sphenoidal bone and

pituitary gland In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The ...

, approximately 1 × 2 cm in size in an adult. The carotid siphon of the internal carotid artery, and cranial nerves III, IV, V (branches V₁ and V₂) and VI all pass through this blood filled space. Both sides of cavernous sinus is connected to each other via intercavernous sinuses. The cavernous sinus lies in between the inner and outer layers of

dura mater In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. ...

Nearby structures

* Above:

optic tract In neuroanatomy, the optic tract () is a part of the visual system in the brain. It is a continuation of the optic nerve that relays information from the optic chiasm to the ipsilateral lateral geniculate nucleus (LGN), pretectal nuclei, and su ...

, optic chiasma, internal carotid artery. * Inferiorly:

foramen lacerum The foramen lacerum ( la, lacerated piercing) is a triangular hole in the base of skull. It is located between the sphenoid bone, the apex of the petrous part of the temporal bone, and the basilar part of the occipital bone. Structure The foram ...

, and the junction of the body and

greater wing of sphenoid bone The greater wing of the sphenoid bone, or alisphenoid, is a bony process of the sphenoid bone; there is one on each side, extending from the side of the body of the sphenoid and curving upward, laterally, and backward. Structure The greater wing ...

. * Medially: pituitary gland (hypophysis cerebri), and

sphenoidal air sinus The sphenoid sinus is a paired paranasal sinus occurring within the within the body of the sphenoid bone. It represents one pair of the four paired paranasal sinuses.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012 ...

. * Laterally:

temporal lobe The temporal lobe is one of the four major lobes of the cerebral cortex in the brain of mammals. The temporal lobe is located beneath the lateral fissure on both cerebral hemispheres of the mammalian brain. The temporal lobe is involved in pro ...

with uncus. * Anteriorly: superior orbital fissure, and the apex of the orbit. * Posteriorly: apex of petrous temporal bone.

Venous connections

The cavernous sinus receives blood from: * Superior and

inferior ophthalmic vein The inferior ophthalmic vein is a vein of the orbit that - together with the superior ophthalmic vein - represents the principal drainage system of the orbit. It begins from a venous network in the front of the orbit, then passes backwards throu ...

s *

Sphenoparietal sinus The sphenoparietal sinus is a paired dural venous sinus situated along the posterior edge of the lesser wing of either sphenoid bone. It drains into the cavernous sinus. Anatomy A sphenoparietal sinus is situated under each lesser wing of the s ...

Superficial middle cerebral vein The middle cerebral veins are the superficial middle cerebral vein and the deep middle cerebral vein. * The superficial middle cerebral vein (superficial Sylvian vein) begins on the lateral surface of the hemisphere, running along the lateral sul ...

s *

Inferior cerebral veins The inferior cerebral veins are veins that drain the undersurface of the cerebral hemispheres and empty into the cavernous and transverse sinuses. Those on the orbital surface of the frontal lobe join the superior cerebral veins, and through th ...

Blood leaves the sinus via superior and

inferior petrosal sinus The inferior petrosal sinuses are two small sinuses situated on the inferior border of the petrous part of the temporal bone, one on each side. Each inferior petrosal sinus drains the cavernous sinus into the internal jugular vein. Structure The ...

es as well as via the emissary veins through the

foramina of the skull This article lists foramina that occur in the human body. __TOC__ Skull The human skull has numerous openings (foramina), through which cranial nerves, arteries, veins, and other structures pass. These foramina vary in size and number, with ...

(mostly through foramen ovale). There are also connections with the

pterygoid plexus The pterygoid plexus (;Entry "pterygoid"
in

of veins via

, deep facial vein and emissary veins.

Apart from the blood which passes through a venous sinus, several anatomical structures, including some

cranial nerves Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and f ...

and their branches, also pass through the sinus. Structures within the outer (lateral) wall of the compartment from superior to inferior: * Oculomotor nerve *

Trochlear nerve The trochlear nerve (), ( lit. ''pulley-like'' nerve) also known as the fourth cranial nerve, cranial nerve IV, or CN IV, is a cranial nerve that innervates just one muscle: the superior oblique muscle of the eye, which operates through the pu ...

* Ophthalmic and maxillary branches of the

trigeminal nerve In neuroanatomy, the trigeminal nerve ( lit. ''triplet'' nerve), also known as the fifth cranial nerve, cranial nerve V, or simply CN V, is a cranial nerve responsible for sensation in the face and motor functions such as biting and chew ...

Structures passing through the midline (medial) wall: *

Abducens nerve The abducens nerve or abducent nerve, also known as the sixth cranial nerve, cranial nerve VI, or simply CN VI, is a cranial nerve in humans and various other animals that controls the movement of the lateral rectus muscle, one of the extraocul ...

* Internal carotid artery accompanied by the

internal carotid plexus The internal carotid plexus is situated on the lateral side of the internal carotid artery, and in the plexus there occasionally exists a small gangliform swelling, the ''carotid ganglion'', on the under surface of the artery. Postganglionic symp ...

These nerves, with the exception of CN V₂, pass through the cavernous sinus to enter the orbital apex through the superior orbital fissure. The maxillary nerve, division V₂ of the trigeminal nerve travels through the lower portion of the sinus and exits via the foramen rotundum. The maxillary branch passes external to, but immediately adjacent to, the lateral wall of the sinus. The

optic nerve In neuroanatomy, the optic nerve, also known as the second cranial nerve, cranial nerve II, or simply CN II, is a paired cranial nerve that transmits visual information from the retina to the brain. In humans, the optic nerve is derived fro ...

lies just above and outside the cavernous sinus, superior and lateral to the

on each side, and enters the orbital apex via the

optic canal The ''optic foramen'' is the opening to the optic canal. The canal is located in the sphenoid bone; it is bounded medially by the body of the sphenoid and laterally by the lesser wing of the sphenoid. The superior surface of the sphenoid bone is b ...

Function

Venous drainage

As a venous sinus, the cavernous sinus receives blood from the superior and

s and from superficial cortical veins, and is connected to the basilar plexus of veins posteriorly. The cavernous sinus drains by two larger channels, the superior and

es, ultimately into the internal jugular vein via the sigmoid sinus, also draining with emissary vein to

pterygoid plexus The pterygoid plexus (;Entry "pterygoid"
in

Clinical significance

It is the only anatomic location in the body in which an

artery An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...

travels completely through a venous structure. If the internal carotid artery ruptures within the cavernous sinus, an ''

arteriovenous fistula An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. It may be congenital, surgically created for hemodialysis treatments, or acquired due to pathologic process, such as trauma or erosion of an arterial ...

'' is created (more specifically, a

carotid-cavernous fistula A carotid-cavernous fistula results from an abnormal communication between the arterial and venous systems within the cavernous sinus in the skull. It is a type of arteriovenous fistula. As arterial blood under high pressure enters the cavernous s ...

). Lesions affecting the cavernous sinus may affect isolated nerves or all the nerves traversing through it. The

lies between the two paired cavernous sinuses. An abnormally growing

pituitary adenoma Pituitary adenomas are tumors that occur in the pituitary gland. Most pituitary tumors are benign, approximately 35% are invasive and just 0.1% to 0.2% are carcinomas.sella turcica The sella turcica (Latin for 'Turkish saddle') is a saddle-shaped depression in the body of the sphenoid bone of the human skull and of the skulls of other hominids including chimpanzees, gorillas and orangutans. It serves as a cephalome ...

, will expand in the direction of least resistance and eventually invade the cavernous sinus. Cavernous sinus syndrome may result from mass effect of these tumors and cause

ophthalmoplegia Ophthalmoparesis refers to weakness (-paresis) or paralysis (-plegia) of one or more extraocular muscles which are responsible for eye movements. It is a physical finding in certain neurologic, ophthalmologic, and endocrine disease. Internal ...

(from compression of the oculomotor nerve, trochlear nerve, and abducens nerve), ophthalmic sensory loss (from compression of the ophthalmic nerve), and maxillary sensory loss (from compression of the maxillary nerve). A complete lesion of the cavernous sinus disrupts CN III, IV, and VI, causing total ophthalmoplegia, usually accompanied by a fixed, dilated pupil. Involvement of CN V (V₁ and variable involvement of V₂) causes sensory loss in these divisions of the trigeminal nerve. Horner's syndrome can also occur due to involvement of the carotid ocular sympathetics, but may be difficult to appreciate in the setting of a complete third nerve injury.Blumenfeld, H, Neuroanatomy through clinical cases. Sinauer Associates, Inc., 2002. Because of its connections with the facial vein via the superior ophthalmic vein, it is possible to get infections in the cavernous sinus from an external facial injury within the danger area of the face. In patients with

thrombophlebitis Thrombophlebitis is a phlebitis (inflammation of a vein) related to a thrombus (blood clot). When it occurs repeatedly in different locations, it is known as thrombophlebitis migrans ( migratory thrombophlebitis). Signs and symptoms The following ...

of the facial vein, pieces of the clot may break off and enter the cavernous sinus, forming a cavernous sinus thrombosis. From there the infection may spread to the dural venous sinuses. Infections may also be introduced by facial lacerations and by bursting pimples in the areas drained by the facial vein.Kumar, P. & Clark, M. Clinical Medicine, 6th ed. Londonn: W.B. Saunders; 2005. Potential causes of cavernous sinus syndrome include metastatic tumors, direct extension of nasopharyngeal tumours, meningioma,

pituitary tumor Pituitary adenomas are tumors that occur in the pituitary gland. Most pituitary tumors are benign, approximately 35% are invasive and just 0.1% to 0.2% are carcinomas.pituitary apoplexy Pituitary apoplexy is bleeding into or impaired blood supply of the pituitary gland. This usually occurs in the presence of a tumor of the pituitary, although in 80% of cases this has not been diagnosed previously. The most common initial sympto ...

aneurysm An aneurysm is an outward bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall. Aneurysms may be a result of a hereditary condition or an acquired disease. Aneurysms can also be a nidus ( ...

s of the intracavernous carotid artery,

, bacterial infection causing cavernous sinus thrombosis, aseptic cavernous sinus thrombosis, idiopathic granulomatous disease ( Tolosa–Hunt syndrome), and fungal infections. Cavernous sinus syndrome is a medical emergency, requiring prompt medical attention, diagnosis, and treatment.

References

External links

* * "Venous dural sinuses." * * * {{Authority control Veins of the head and neck Medical mnemonics