Spinal cord blood supply

The blood supply to the spinal cord is carried out by the anterior and paired posterior spinal arteries, as well as by the radicular-spinal arteries.

Located on the anterior surface of the spinal cord, the artery begins from two vertebral arteries and branches (called the spinal arteries) that extend from the intracranial part of the vertebral arteries, which soon merge and form a common trunk that runs down along the anterior groove of the ventral surface of the spinal cord.

Two posterior spinal arteries, starting from the vertebral arteries, run along the dorsal surface of the spinal cord directly at the posterior roots: each artery consists of two parallel stems, one of which is located medially, and the other – lateral to the posterior roots.

Spinal arteries from the vertebral arteries supply blood only 2-3 upper cervical segments, throughout the rest of the length, the spinal cord is nourished by the radicular-spinal arteries, which in the cervical and / thoracic regions receive blood from the branches of the vertebral and ascending cervical arteries (subclavian artery system) , and below – from the intercostal and lumbar arteries extending from the aorta. From the intercostal artery, the dorsal-spinal artery departs, which is divided into the anterior and posterior radicular-spinal arteries. The latter, having passed through the intervertebral foramen, go along with the nerve roots. Blood from the anterior radicular arteries enters the anterior spinal artery, and from the posterior to the posterior spinal artery.

The anterior radicular arteries are smaller than the posterior ones, but they are larger. The number of arteries varies from 4 to 14 (usually 5-8). In the cervical spine, in most cases, there are 3. The upper and middle parts of the thoracic spinal cord (from D3 to D8) are fed by 2-3 thin anterior radicular arteries.
The lower thoracic, lumbar and sacral parts of the spinal cord are supplied with 1-3 arteries. The largest of them (2 mm in diameter) is called the lumbar thickening artery or Adamkevich’s artery. Switching off the artery of the lumbar thickening gives a characteristic clinical picture of a spinal cord infarction with severe symptoms. Starting from the 10th, and sometimes from the 6th thoracic segment, it feeds the entire lower part of the spinal cord. Adamkevich’s artery enters the spinal canal usually with one of the roots from D8 to L4, more often from the X, XI or XII thoracic root, in 75% of cases – on the left and in 25% – on the right.

In some cases, in addition to Adamkevich’s artery, small arteries are found entering from the VII, VIII or IX root, and an artery entering from the V lumbar or I sacral root, supplying the cone and epicone of the spinal cord.
This is the Degrozh-Gotteron artery. There are about 20 posterior radicular arteries; they are smaller in caliber than the front ones.

A large number of “central arteries” depart from the anterior spinal artery at a right angle, which run along the anterior spinal groove and, near the anterior gray commissure, enter the substance of the spinal cord, either in the right or in its left half. The central arteries feed the anterior horns, the base of the posterior horns, Clark’s columns, the anterior columns, and most of the lateral columns of the spinal cord. Thus, the anterior spinal artery supplies approximately 4/5 of the spinal cord diameter.

The branches of the posterior spinal arteries enter the region of the posterior horns and feed, besides them, almost entirely the posterior columns and a small part of the lateral columns.

Both posterior spinal arteries are connected to each other and to the anterior spinal artery using the horizontal arterial trunk,
which run along the surface of the spinal cord and form a vascular ring around it – Vasa corona. Perpendicularly from this ring, multiple trunks extend into the spinal cord. Inside the spinal cord, between the vessels of the adjacent segments, as well as between the vessels of the right and left sides, there are abundant anastomoses, from which the capillary network is formed, which is thicker in the gray matter than in the white.

The spinal cord has a highly developed venous system. The veins draining the anterior and posterior parts of the spinal cord have a “watershed” approximately in the same place as the arteries. The main venous canals, which receive the blood of the veins from the spinal cord, run in the longitudinal direction similar to the arterial trunks. At the top, they connect to the veins of the base of the skull, forming a continuous venous tract. The veins of the spinal cord also have a connection with the venous plexuses of the spine, and through them – with the veins of the body cavities.

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