Internal carotid artery

internal carotid arteriesinternal carotidinternalcarotid siphoncarotid arteryCavernous part of internal carotid arteryPetrous portion of the internal carotid arterycarotidcarotid artery, internalcavernous carotid artery
The internal carotid artery is located in the inner side of the neck in contrast to the external carotid artery.wikipedia
168 Related Articles

External carotid artery

external carotidexternal carotid arteriesexternal
The internal carotid artery is located in the inner side of the neck in contrast to the external carotid artery.
It arises from the common carotid artery when it splits into the external and internal carotid artery.

Carotid sinus

Carotid sinus massagecarotid sinus reflexCarotid sinus stimulation
This part of the artery is known as the carotid sinus or the carotid bulb.
In human anatomy, the carotid sinus is a dilated area at the base of the internal carotid artery just superior to the bifurcation of the internal carotid and external carotid at the level of the superior border of thyroid cartilage.

Scalp

scalp hair
In human anatomy, they arise from the common carotid arteries where these bifurcate into the internal and external carotid arteries at cervical vertebral level 3 or 4; the internal carotid artery supplies the brain including eyes, while the external carotid nourishes other portions of the head, such as face, scalp, skull, and meninges.

Carotid canal

The cervical segment, or C1, or cervical part of the internal carotid, extends from the carotid bifurcation until it enters the carotid canal in the skull anterior to the jugular foramen. The internal carotid runs vertically upward in the carotid sheath and enters the skull through the carotid canal. The artery is separated from the bony wall of the carotid canal by a prolongation of dura mater, and is surrounded by a number of small veins and by filaments of the carotid plexus, derived from the ascending branch of the superior cervical ganglion of the sympathetic trunk.
The carotid canal is the passageway in the temporal bone through which the internal carotid artery enters the middle cranial fossa from the neck.

Vagus nerve

vagusvagalcranial nerve X
Higher up, it is separated from the external carotid by the styloglossus and stylopharyngeus muscles, the tip of the styloid process and the stylohyoid ligament, the glossopharyngeal nerve and the pharyngeal branch of the vagus nerve.
Upon leaving the medulla oblongata between the olive and the inferior cerebellar peduncle, the vagus nerve extends through the jugular foramen, then passes into the carotid sheath between the internal carotid artery and the internal jugular vein down to the neck, chest, and abdomen, where it contributes to the innervation of the viscera, reaching all the way to the colon.

Occipital artery

occipital arteriesoccipital
It is relatively superficial at its start, where it is contained in the carotid triangle of the neck, and lies behind and medial to the external carotid, overlapped by the sternocleidomastoid muscle, and covered by the deep fascia, the platysma, and integument: it then passes beneath the parotid gland, being crossed by the hypoglossal nerve, the digastric muscle and the stylohyoid muscle, the occipital artery and the posterior auricular artery.
At its origin, it is covered by the posterior belly of the digastricus and the stylohyoideus, and the hypoglossal nerve winds around it from behind forward; higher up, it crosses the internal carotid artery, the internal jugular vein, and the vagus and accessory nerves.

Styloglossus

Styloglossus muscle
Higher up, it is separated from the external carotid by the styloglossus and stylopharyngeus muscles, the tip of the styloid process and the stylohyoid ligament, the glossopharyngeal nerve and the pharyngeal branch of the vagus nerve.
Passing inferiorly and anteriorly between the internal and external carotid arteries, it divides upon the side of the tongue near its dorsal surface, blending with the fibers of the longitudinalis inferior in front of the hyoglossus; the other, oblique, overlaps the Hyoglossus and decussates with its fibers.

Hypoglossal nerve

hypoglossalXIILingual branches of hypoglossal nerve
It is relatively superficial at its start, where it is contained in the carotid triangle of the neck, and lies behind and medial to the external carotid, overlapped by the sternocleidomastoid muscle, and covered by the deep fascia, the platysma, and integument: it then passes beneath the parotid gland, being crossed by the hypoglossal nerve, the digastric muscle and the stylohyoid muscle, the occipital artery and the posterior auricular artery.
It then travels close to the vagus nerve and spinal division of the accessory nerve, spirals downwards behind the vagus nerve and passes between the internal carotid artery and internal jugular vein lying on the carotid sheath.

Glossopharyngeal nerve

glossopharyngealIXCN IX
Higher up, it is separated from the external carotid by the styloglossus and stylopharyngeus muscles, the tip of the styloid process and the stylohyoid ligament, the glossopharyngeal nerve and the pharyngeal branch of the vagus nerve.
In its passage through the foramen (with X and XI), the glossopharyngeal nerve passes between the internal jugular vein and internal carotid artery.

Superior cervical ganglion

superior cervical gangliasuperior
It is in relation, behind, with the longus capitis, the superior cervical ganglion of the sympathetic trunk, and the superior laryngeal nerve; laterally, with the internal jugular vein and vagus nerve, the nerve lying on a plane posterior to the artery; medially, with the pharynx, superior laryngeal nerve, and ascending pharyngeal artery. The artery is separated from the bony wall of the carotid canal by a prolongation of dura mater, and is surrounded by a number of small veins and by filaments of the carotid plexus, derived from the ascending branch of the superior cervical ganglion of the sympathetic trunk.
It lies deep to the sheath of the internal carotid artery and internal jugular vein, and anterior to the Longus capitis muscle.

Carotid sheath

The internal carotid runs vertically upward in the carotid sheath and enters the skull through the carotid canal.

Internal carotid plexus

carotid plexus
The artery is separated from the bony wall of the carotid canal by a prolongation of dura mater, and is surrounded by a number of small veins and by filaments of the carotid plexus, derived from the ascending branch of the superior cervical ganglion of the sympathetic trunk.
The internal carotid plexus (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.

Internal jugular vein

internal jugularinternal jugular veinsIJV veins
It is in relation, behind, with the longus capitis, the superior cervical ganglion of the sympathetic trunk, and the superior laryngeal nerve; laterally, with the internal jugular vein and vagus nerve, the nerve lying on a plane posterior to the artery; medially, with the pharynx, superior laryngeal nerve, and ascending pharyngeal artery.
It runs down the side of the neck in a vertical direction, being at one end lateral to the internal carotid artery, and then lateral to the common carotid artery, and at the root of the neck, it unites with the subclavian vein to form the brachiocephalic vein (innominate vein); a little above its termination is a second dilatation, the inferior bulb.

Trigeminal ganglion

trigeminal gangliaGasserian ganglionSemilunar ganglion
Farther forward it is separated from the trigeminal ganglion by a thin plate of bone, which forms the floor of the fossa for the ganglion and the roof of the horizontal portion of the canal.
It is somewhat crescent-shaped, with its convexity directed forward: Medially, it is in relation with the internal carotid artery and the posterior part of the cavernous sinus.

Superior laryngeal nerve

internal laryngeal nerveexternal laryngeal nerveexternal laryngeal
It is in relation, behind, with the longus capitis, the superior cervical ganglion of the sympathetic trunk, and the superior laryngeal nerve; laterally, with the internal jugular vein and vagus nerve, the nerve lying on a plane posterior to the artery; medially, with the pharynx, superior laryngeal nerve, and ascending pharyngeal artery.
The superior laryngeal nerve descends, by the side of the pharynx, behind the internal carotid artery, and divides into two branches —the external laryngeal nerve and the internal laryngeal nerve.

Foramen lacerum

This segment extends until the foramen lacerum. The lacerum segment, or C3, is a short segment that begins above the foramen lacerum and ends at the petrolingual ligament, a reflection of periosteum between the lingula and petrous apex (or petrosal process) of the sphenoid bone.
The internal carotid artery passes from the carotid canal in the base of the skull, emerging and coursing superior to foramen lacerum as it exits the carotid canal.

Cavernous sinus

cavernous sinusescavernouscavernous sinus syndrome
The cavernous segment is surrounded by the cavernous sinus.
The carotid siphon of the internal carotid artery, and cranial nerves III, IV, V (branches V 1 and V 2 ) and VI all pass through this blood filled space.

Ophthalmic artery

ophthalmicartery to the eyeLateral muscular branch
The clinoid segment normally has no named branches, though the ophthalmic artery may arise from the clinoid segment.
The ophthalmic artery (OA) is the first branch of the internal carotid artery distal to the cavernous sinus.

Sympathetic trunk

sympathetic chainsympathetic trunkscervical sympathetic chain
It is in relation, behind, with the longus capitis, the superior cervical ganglion of the sympathetic trunk, and the superior laryngeal nerve; laterally, with the internal jugular vein and vagus nerve, the nerve lying on a plane posterior to the artery; medially, with the pharynx, superior laryngeal nerve, and ascending pharyngeal artery.
The superior end of it is continued upward through the carotid canal into the skull, and forms a plexus on the internal carotid artery; the inferior part travels in front of the coccyx, where it converges with the other trunk at a structure known as the ganglion impar.

Anterior cerebral artery

Anterior cerebralanterior cerebral arteriesinfarction, anterior cerebral artery
The internal carotid then divides to form the anterior cerebral artery and middle cerebral artery.
The two anterior cerebral arteries arise from the internal carotid artery and are part of the circle of Willis.

Anterior choroidal artery

Anterior choroidalChoroid
The anterior choroidal artery originates from the internal carotid artery.

Petrolingual ligament

The lacerum segment, or C3, is a short segment that begins above the foramen lacerum and ends at the petrolingual ligament, a reflection of periosteum between the lingula and petrous apex (or petrosal process) of the sphenoid bone.
The petrolingual ligament lies at the posteroinferior aspect of the lateral wall of the cavernous sinus and marks the point at which the internal carotid artery enters the cavernous sinus.

Middle cerebral artery

Middle cerebralinfarction, middle cerebral arterymiddle cerebral arteries
The internal carotid then divides to form the anterior cerebral artery and middle cerebral artery.
The MCA arises from the internal carotid and continues into the lateral sulcus where it then branches and projects to many parts of the lateral cerebral cortex.

Abducens nerve

abducent nerveabducensVI
This portion of the artery is surrounded by filaments of the sympathetic trunk and on its lateral side is the abducent nerve, or cranial nerve VI.
In the cavernous sinus it runs alongside the internal carotid artery.

Caroticotympanic arteries

caroticotympanic arterycaroticotympanic branchprimitive hyoid artery
The caroticotympanic arteries (tympanic branch) are small branches of the internal carotid artery; they enter the tympanic cavity through a minute foramen in the carotid canal, and anastomose with the anterior tympanic branch of the internal maxillary, and with the posterior tympanic branch of the stylomastoid artery.