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Cerebral Arteries

Q: What are the functions and branches of the ophthalmic artery?

The ophthalmic artery (a. ophthalmica) supplies the eyeball and provides a connection between the internal and external carotid artery systems. By giving off numerous branches, it performs the following functions: Lacrimal artery (a. lacrimalis) — supplies the lacrimal gland and eyelids.Central retinal artery (a. centralis retinae) — supplies the retina.Short and long posterior ciliary arteries (aa. ciliares posteriores breves et longae) — supply the choroid and ciliary body.Muscular branches (aa. musculares) — supply the extraocular muscles.Posterior and anterior ethmoidal arteries (a. ethmoidalis posterior, a. ethmoidalis anterior) — supply the mucosa of the ethmoidal labyrinth, sphenoid sinus, nasal cavity, and the dura mater of the anterior cranial fossa.Supraorbital and supratrochlear arteries (a. supraorbitalis, a. supratrochlearis) — supply the skin of the forehead, the frontal belly of the occipitofrontalis muscle (m. occipitofrontalis), and the upper eyelid.Dorsal nasal artery (a. dorsalis nasi) — supplies the dorsum of the nose.

Q: What structures are supplied by the central thalamostriate arteries?

The central thalamostriate arteries (aa. centrales anterolaterales or aa. thalamostriatae) supply several deep structures of the brain. Penetrating through the anterior perforated substance, they supply the following structures: Caudate nucleus — receives blood supply from the central arteries.Internal capsule — supplied by thalamostriate branches.Putamen (putamen) — also supplied by these vessels.

Arteriae cerebri

For medical students3 min readUpdated 2026-10-10

The blood supply system of the brain is a complex network of vessels originating primarily from the internal carotid artery system. They nourish the cerebral cortex and subcortical structures, and form a closed anastomotic ring at the base of the brain to protect neural tissue from ischemia.

Main AnastomosisThe Circle of Willis compensates for blood flow deficits during the occlusion of major vessels.

Stroke ZoneThe middle cerebral artery is the most frequent target for ischemic strokes of the brain.

Largest BranchThe middle cerebral artery is the largest branch of the internal carotid artery.

Vascular ConnectionThe ophthalmic artery connects the external and internal carotid artery systems.

Anterior Cerebral Artery

Hemispheric blood supply is based on major vessels that represent terminal branches of the internal carotid artery (a. carotis interna).

The anterior cerebral artery (a. cerebri anterior) courses anteriorly and medially, positioned directly above the optic nerve. It then enters the longitudinal cerebral fissure and runs along the medial surface of the hemisphere. The vessel curves around the genu of the corpus callosum (genu corporis callosi) and extends toward the occipital lobe.

Its territory includes:

Anterior central arteries (aa. centrales anteromediales) — supply the basal nuclei, including the internal capsule and caudate nucleus.
Anterior communicating artery (a. communicans anterior) — connects the two anterior cerebral arteries at the level of the optic chiasm.
Postcommunicating part (a. pericallosa) — gives rise to the arteries supplying the medial surface of the frontal lobe (a. frontobasalis medialis), the branch along the corpus callosum (a. callosomarginalis), frontal branches, the branch to the paracentral lobule (motor representation of the lower limb), and the precuneus.

Overall, this artery supplies the medial segments of the frontal and parietal lobes, as well as the upper parts of the postcentral and precentral gyri.

Middle Cerebral Artery

The middle cerebral artery (a. cerebri media) is the largest branch of the internal carotid artery. Its course runs deep within the lateral sulcus (sulcus lateralis), where it divides into sphenoidal (pars sphenoidalis), insular (pars insularis), and cortical (pars corticalis) parts. This vessel supplies most of the lateral surface of the hemispheres, including Broca's and Wernicke's speech centers, as well as the cortical areas for motor and sensory control of the face and upper limb.

Key branches:

Central thalamostriate arteries — penetrate deeply through the anterior perforated substance, supplying the putamen (putamen), internal capsule, and caudate nucleus.
Frontobasal arteries — travel toward the inferior surface of the frontal lobe.
Temporal arteries (anterior, middle, and posterior) — supply the temporal lobe.
Central sulcal arteries — run to the pre- and postcentral gyri.
Parietal arteries — supply the parietal region.
Angular gyrus artery (a. gyri angularis) — forms anastomoses with the posterior cerebral artery territory.

Choroidal and Posterior Communicating Arteries

In addition to the main trunks, other important vessels branch off the posterior surface of the internal carotid artery.

The anterior choroidal artery (a. choroidea anterior) courses laterally, running parallel to the cerebral peduncle. It penetrates the substance of the temporal lobe, ultimately reaching the choroid plexus of the lateral ventricle. Along its path, it gives off branches to the globus pallidus, amygdala, optic tract, internal capsule, caudate nucleus, and lateral geniculate body.

The posterior communicating artery (a. communicans posterior) runs posteriorly, connecting the internal carotid artery to the posterior cerebral artery. It supplies the optic chiasm, hypothalamus (including the tuber cinereum), and midbrain structures—specifically the red nucleus and substantia nigra.

Arterial Circle of the Brain (Circle of Willis)

A unique structure at the base of the brain is the cerebral arterial circle (circulus arteriosus cerebri). This is a closed anastomotic system that plays a critical role in maintaining stable cerebral perfusion.

How it is formed:

Anteriorly: The right and left anterior cerebral arteries are connected via the anterior communicating artery (a. communicans anterior).
Laterally: The internal carotid artery is connected to the posterior cerebral artery via the posterior communicating artery (a. communicans posterior).
Posteriorly: The branches of the basilar artery (a. basilaris) contribute to the formation of the circle.

The primary significance of this circle is the establishment of collateral circulation. If a major artery is narrowed or occluded, blood can flow from the opposite side, compensating for the deficiency.

Clinical Significance:

The territory of the a. cerebri media is the most common site of ischemic stroke. Occlusion leads to aphasia and contralateral hemiparesis affecting the face and arm.
The ophthalmic artery (a. ophthalmica) is the first intracranial branch and serves as an important anastomotic link between the internal and external carotid artery systems.

Mnemonic

To remember the components of the Circle of Willis, imagine a hexagon at the base of the brain: anteriorly, the two anterior cerebral arteries are joined by the anterior communicating artery; laterally run the posterior communicating arteries; and the posterior base is formed by the posterior cerebral arteries.

Frequently asked questions

What are the functions and branches of the ophthalmic artery?

The ophthalmic artery (a. ophthalmica) supplies the eyeball and provides a connection between the internal and external carotid artery systems. By giving off numerous branches, it performs the following functions:

Lacrimal artery (a. lacrimalis) — supplies the lacrimal gland and eyelids.
Central retinal artery (a. centralis retinae) — supplies the retina.
Short and long posterior ciliary arteries (aa. ciliares posteriores breves et longae) — supply the choroid and ciliary body.
Muscular branches (aa. musculares) — supply the extraocular muscles.
Posterior and anterior ethmoidal arteries (a. ethmoidalis posterior, a. ethmoidalis anterior) — supply the mucosa of the ethmoidal labyrinth, sphenoid sinus, nasal cavity, and the dura mater of the anterior cranial fossa.
Supraorbital and supratrochlear arteries (a. supraorbitalis, a. supratrochlearis) — supply the skin of the forehead, the frontal belly of the occipitofrontalis muscle (m. occipitofrontalis), and the upper eyelid.
Dorsal nasal artery (a. dorsalis nasi) — supplies the dorsum of the nose.

What structures are supplied by the central thalamostriate arteries?

The central thalamostriate arteries (aa. centrales anterolaterales or aa. thalamostriatae) supply several deep structures of the brain. Penetrating through the anterior perforated substance, they supply the following structures:

Caudate nucleus — receives blood supply from the central arteries.
Internal capsule — supplied by thalamostriate branches.
Putamen (putamen) — also supplied by these vessels.

Which artery supplies the paracentral lobule?

This region, which contains the motor representation of the lower limb, is supplied by a branch of the anterior cerebral artery—the paracentral branch (r. paracentralis).

Occlusion of which vessel most commonly results in aphasia?

Speech impairment (aphasia) combined with contralateral hemiparesis of the face and arm typically develops during an ischemic stroke in the territory of the middle cerebral artery, which supplies Broca's and Wernicke's areas.

What structures are supplied by the anterior choroidal artery?

It provides blood to the caudate nucleus, globus pallidus, internal capsule, amygdala, optic tract, and lateral geniculate body.

What is the primary function of the Circle of Willis?

It forms a closed ring of collateral circulation at the base of the brain. In the event of an occlusion of one of the vessels, this network allows for the compensation of blood supply deficits.

Go deeper

Cortical and central branches of the middle cerebral artery
Anastomoses between the ophthalmic artery and the external carotid artery
Topography of the insular and sphenoidal parts of the middle cerebral artery
Detailed blood supply of the internal capsule and basal nuclei
Anatomical variations of the cerebral arterial circle