The nerves supply the arteries

Anatomy of the central nervous system: vessels and blood supply

Table of Contents


Image: “Arteries of the head” by Henry Gray. License: Public Domain


Arteries in the head and neck area

Anterior and posterior circulation of the CNS

The head and neck areas are essentially made up of the two Carotids (Aa. carotides communes) that arise from the aortic arch. The common artery divides into one External carotid artery, which supplies the neck area including, for example, the thyroid gland, tongue, parts of the face and the skullcap and some jaw muscles, and into one Internal carotid arterywhich, along with other small supply areas, is primarily responsible for the intracerebral blood supply. In addition, one originates from the internal carotid artery A. ophthalmica to care for the eyes.

Through the Carotid Canal the internal carotid artery enters the brain and branches into the Aa. cerebri media and anterior on. This represents the so-called front part of the circulation, which is also Circulus arteriosus cerebri or Circulus arteriosus Willisii is called.

The back of the circuit is through the two Aa. vertebralthat from the Aa. subclaviae spring, formed. After branches have been given off to the spinal cord and the cerebellum, the two Aa unite. vertebral to unpaired A. basilaris, from which in turn the paired A. cerebri posterior arises. Through so-called Communicating arteries the circuit is closed between the large cerebral arteries.

Image: “Schematic representation of the circle of Willis, arteries of the brain and brain stem” by Rhcastilhos. License: Public Domain

Blood supply to the spinal cord

Aa. Spinales and vertebral venous plexus in the CNS

The arterial blood supply to the spinal cord takes place through the Aa. anterior spinal and posteriores, each from the Aa. vertebralis and pull down vertically along the spinal cord. The anterior spinal artery runs unpaired ventrally, the aa. spinales posteriores in pairs dorsal to the spinal cord.

The spinal arteries receive further caudal inflow from the for their own supply Rr. (Rami) spinalesthat come from the rr. dorsales of the Aa. intercostales posteriores arise, which in turn come from the aorta go off.

Venous outflow in the CNS

The venous outflow takes place via the individually available Vv. Spinales anterior and posterior. These are in turn connected to the venous plexuses that accompany the spinal cord along its entire length (Plexus venosus vertebralis internus and externus), which are located in the epidural space between the dura mater and the vertebral bones. From here the blood is returned to the body's circulation.

Image: “Venous plexus of the spinal cord” by Henry Gray. License: Public Domain

Infarction of the anterior spinal artery

The so-called Anterior spinal artery syndrome arises from an incomplete or complete occlusion of the anterior spinal artery supplying the spinal cord. Such an anterior spinal infarction can initially result in acute pain, paresthesia and a loss of temperature and pain sensation in the patient caudal to the location of the arterial disorder. The function of the rectum and bladder can be impaired. Above all, however, the syndrome impresses with incomplete paralysis on both sides (Paraparesis), which also occurs below the lesion site.

Anterior and posterior circulatory arteries with coverage area

The paired ones are part of the front circuit Aa. cerebri anterior and mediathat arise from the two carotids. The posterior circulation is created by the union of the Aa. vertebral to unpaired A. basilaris formed from which in turn the paired A. cerebri posterior arises. over Communicating arteries (anterior and posterior) the anterior, middle and posterior cerebral arteries are connected to one another to form a circular arteriosus.

The supply areas of the respective cerebral arteries flow into one another, but some structures can be relatively clearly assigned to the arteries from which they are supplied:

  1. A. cerebri anterior: This artery supplies the Medial surfaces of the cortex of both hemispheres including the Mantle edge and a bit of convexity beyond that. For example, part of the sensorimotor cortex is located here. It also reaches the frontal pole.
  2. A. cerebri media: The lateral parts of the convexity both hemispheres are predominantly supplied by it. Also Basal ganglia and Internal capsule receive the lion's share of its inflow from the A. cerebri media, just like the two Language centers (Broca and Wernicke).
  3. A. cerebri posterior: It's mainly for that occipital pole responsible, in which the Visual cortex lies. In addition, parts of the Temporal lobe in your coverage area.

Image: “Supply areas of the three large cerebral arteries: A. cerebri anterior (blue), A. cerebri media (red), A. cerebri posterior (yellow)” by Henry Gray. License: Public Domain

Diseases of the blood supply to the brain

The most prominent and well-known disease that affects the brain is stroke. Strokes can have different causes. In the vast majority of cases, they are supported by a ischemic cerebral infarction, i.e. an occlusion or stenosis and the resulting reduced blood flow to the brain tissue. The other part is going through Cerebral hemorrhage triggered in different areas and by other rarer etiologies.

The cerebral hemorrhages themselves can in turn be divided into:

  • Image: “Subarachnoid hemorrhage on computed tomography. One recognizes the hyperdense blood in the basal cisterns ”by Hellerhoff. License: CC BY-SA 3.0

    Intracerebral or parenchymal Bleeding: Bleeding from the small blood vessels in the brain tissue

  • Epidural bleeding (extracerebral): Hemorrhage into the space between the skull bone and the dura mater with hematoma formation, mostly due to a tear in the A. meningea media, for example due to trauma; becomes rarer with age
  • Subdural bleeding (extracerebral): Hemorrhage in the space between the dura mater and the arachnoid due to the rupture of the bridge veins there
  • Subarachnoid hemorrhage (extracerebral): bleeding into the subarachnoid space, e.g. through a ruptured aneurysm (often the middle cerebral artery)

There is also the concept of intraventricular bleedingwhich means that there is blood in the cerebral ventricles. This can be due to different etiologies, one possible cause being subarachnoid hemorrhage.

Overview: veins of the brain and the neck and head area

The venous outflow takes place through various venous systems, all of which are in the brain's own Sinus durae matris flow out. The drainage from inside the brain takes place via the so-called deep cerebral veins, including the V. interior cerebri and V. magna cerebri into the rectus sinus.

The brain surface is about diverse superficial cerebral veins drained, which in turn connects to the Sagittal sinus win (and along the way form the bridging veins that play a crucial role in the formation of subdural hematomas).

The sinus durae matris are dural duplicates that collect blood from the brain and mainly via the Internal jugular vein, which joins the subclavian vein to form the brachiocephalic vein, back to the heart. The extracranial veins for supplying the scalp and the outer skull are also partly received via so-called Emissaries Connection to the sinuses of the brain.

Most of the outside of the skull and the neck are drained via veins, which in turn enter the Vv. Jugulares externa and anterior flow out. In turn, these two jugular veins usually open into the subclavian vein.

Popular exam questions about vessels and blood supply to the CNS

The correct answers can be found below the references.

1. Which statement about epidural bleeding is correct?

  1. It is caused by a rupture of the bridge veins.
  2. An epidural hematoma is a disease of old age.
  3. An epidural hematoma usually occurs for no apparent cause.
  4. Often a lesion of the middle meningeal artery is the cause.
  5. The additional occurrence of blood in the ventricles is typical.

2. What is not in the supply area of ​​the A. cerebri media?

  1. The basal ganglia
  2. The visual cortex
  3. Part of the sensorimotor cortex
  4. Large parts of the internal capsule
  5. The Broca Language Center

3. From which artery does the ophthalmic artery arise?

  1. Internal carotid artery
  2. A. cerebri anterior
  3. A. cerebri media
  4. A. meningea media
  5. External carotid artery


Understand the brain - anatomy and functions

This free eBook contains all the important basics of neuroanatomy for the Physikum. You will also receive on the subject of the brain

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✔ Control questions after each section

✔ Further reading recommendations

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Dual anatomy series, 2nd edition - Thieme Verlag

Prometheus Learning Atlas of Anatomy: Head, Neck and Neuroanatomy, 3rd Edition - Thieme Verlag

Anterior spinal syndrome via flexikon.doccheck.com

Spinal infarction via link.springer.com

Solutions to the questions: 1D, 2B, 3A

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