Internal carotid artery

The internal carotid artery (a.carotis interna) supplies the brain and the organ of vision. The internal carotid artery is distinguished by cervical, stony, cavernous and cerebral parts. On the neck, this artery does not give branches. The cervical part (pars cervicalis) is located laterally and posteriorly, and then medially from the external carotid artery. Between the throat medially and the internal jugular vein laterally, the inner carotid artery rises vertically upward to the external opening of the carotid canal. Behind and medially from the internal carotid artery are the sympathetic trunk and the vagus nerve, in front and laterally the hyoid nerve, above the glossopharyngeal nerve. In the sleepy channel is the stony part (pars petrosa) of the internal carotid artery, which forms a bend and delivers into the tympanum the thin sleepy-tympanic arteries (aa.carotico-tympanicae).

Upon exiting from the carotid canal, the internal carotid artery makes a bend upward, lies in the short eponymous furrow of the sphenoid bone. In the thickness of the cavernous sinus of the hard shell of the brain is located the cavernous part (pars cavernosa) of the artery. At the level of the visual channel is the cerebral part (pars cerebralis), here the artery makes one more bend, facing the bulge forward. At this point, the eye artery is removed from the internal carotid artery. At the inner edge of the anterior inclined process, the internal carotid artery divides into its terminal branches, the anterior and middle cerebral arteries.

The ocular artery (a.ophthalmica) departs in the region of the last bend of the internal carotid artery and, together with the optic nerve, enters through the optic canal into the orbit. Then the eye artery follows the medial wall of the orbit to the medial corner of the eye, where it splits into its terminal branches - the medial arteries of the eyelids and the dorsal artery of the nose.

The following branches leave the eye artery:

1. the lacrimal artery (a.lacrimalis) follows between the upper and lateral rectus muscles of the eye, giving them branches, to the lacrimal gland; the lateral arteries of the eyelids (aa.palpebrales laterales) are also separated from the lacrimal artery;
2. long and short posterior ciliated arteries (aa.ciliares posteriores longae et breves) perforate the sclera and penetrate into the choroid of the eye;
3. the central artery of the retina (a.centralis retinae) enters the optic nerve and reaches the retina;
4. Muscle arteries (aa.musculares) go to the upper straight and oblique muscles of the eyeball. From the muscular arteries, the anterior ciliary arteries (aa.ciliares anteriores, total 5-6) branch out and enter the anterior parts of the sclera of the eyeball, terminate in the iris, and the anterior conjunct and the arteries (aa.conjuctivales anteriores) that go to the conjunctiva of the eye ;
5. the posterior trellis artery (a.ethmoidalis posterior) follows the mucosa of the posterior cells of the latticed bone through the posterior trellised opening;
6. The anterior grating artery (a.ethmoidalis anterior) passes through the front latticework, where it divides into its terminal branches. One of these branches - the anterior meningeal branch (r.meningeus anterior) enters the cavity of the skull and blood supply to the hard shell of the brain. Other branches penetrate the latticed plate of the latticed bone and nourish the mucosa of the latticed cells, as well as the anterior sections of the side walls and the septum of the nose;
7. the supraorbital artery (a.supraorbitalis) departs from the eye artery in the place where it passes over the optic nerve. The supraorbital artery is attached to the upper wall of the orbit. Then, in the area of the supraorbital notch, it turns upward (along with the eponymous nerve), branches into the muscles and the skin of the forehead;
8. the medial arteries of the eyelids (aa.palpebrales mediales) are the terminal branches of the eye artery, are directed to the medial corner of the eye, anastomose with the lateral arteries of the eyelids (from the lacrimal artery) and form two arterial arcs: the arc of the upper eyelid (arcus palpebralis superior) and arch of the lower eyelid arcus palpebralis inferior);
9. dorsal artery of the nose (a.dorsalis nasi) - the terminal branch of the eye artery, passes through the circular muscle to the angle of the eye above the medial ligament of the eyelids, gives the branches to the lacrimal sac and passes to the back of the nose. This artery anastomoses with the angular artery (the terminal branch of the facial artery).

The anterior cerebral artery (a.cerebri anterior) departs from the internal carotid artery slightly above the eye artery, extends forward above the optic nerve, approaches the same-named artery of the opposite side and joins it with a short unpaired anterior connective artery (a.communicans anterior). Then the anterior cerebral artery turns up on the medial surface of the cerebral hemisphere, lies in the furrow of the corpus callosum, rounds the corpus callosum and heads toward the occipital lobe of the large brain. The artery supplies the medial side of the frontal, parietal and partly occipital lobes, as well as olfactory bulbs, tracts and the striatum. To the substance of the brain, the artery gives off two groups of branches - cortical and central (deep).

The middle cerebral artery (a.cerebri media) is the largest branch of the internal carotid artery. It goes to the lateral side, into the deep lateral furrow, along the surface of the islet part (islet) and divides into its terminal branches, the blood supplying islet and the upper-lateral divisions of the frontal, temporal and parietal lobes of the cerebral hemisphere. In the middle cerebral artery the following parts are distinguished: the wedge-shaped part (pars sphenoidalis), adjacent to the large wing of the sphenoid bone, the islet part (pars insularis) and the terminal (cortical) part (pars terminalis, s. Pars corticalis).

The posterior connective artery (a.communicans posterior) departs from the internal carotid artery until separation of the latter into the anterior and middle cerebral arteries. It is directed posteriorly and slightly to the side of the bridge and at its anterior margin it enters the posterior cerebral artery (branch of the basilar artery).

The anterior villous artery (a.choroidea anterior) is a thin vessel that extends from the inner carotid artery behind the posterior connective artery, goes posteriorly along the cerebral foreleg and approaches the posterior sections of the temporal lobe. Artery enters the substance of the brain, branched into the walls of the lower horn of the lateral ventricle, and participates in the formation of its vascular plexus. The anterior villous artery gives branches to the visual tract, the lateral geniculate body, the inner capsule, the basal nuclei, the nuclei of the hypothalamus and to the red nucleus.

Between the branches of the internal and external carotid arteries there are anastomoses that play an important role in the distribution of blood in the head region.

[1], [2], [3], [4], [5], [6], [7],