Blood supply to the spinal cord
Blood supply to the spinal cord are by the following
Arteries
1. Vertebral artery
cervical branches : these are the spinal branches
they enter through the intervertebral formina
(they divide into two:-
one passing along the roots of the nerves to supply the spinal cord
the other divides into an ascending and a descending branches
they unite with the similar branches from the arteries above and below two lateral anstomotic chains on the posterior surfacs of the bodies of the vertebrae near the atttachment of the pedicles.)
2. Anterior spinal artery
A small branch
Arises near the termination of the vertebral artery
It descends in front of the medulla oblongata and unites with its fellow of the opposite side becomes a single artery
It runs along the front of the cord reinforced by spinal branches derived from the above mentioned arteries.
It forms the anterior median artery
Extends as far as the lower part of the spinal cord - continues as a slender twig on the filum terminale.
This vessel is in the piamater along the anterior median fissure.
3 Posterior spinal arteries
One or two on each side
Derived from the vertebral artery
at the level of foramen magnum
at the side of the medulla oblongata.
Spinal twigs from
4. Ascending cervical artery
5. Posterior intercostal arteries
6. First lumbar artery
All these arteries enter the vertebral canal through the intervertebral foramina; by means of these brnches the posterior spinal arteries are continued to the lower part of the spinal cord.
Venous Drainage
6 tortuous veins.
Often plexiform and longitudinal channels,
one along the anterior median fissue and a sccond along the posterior median sulcus
others often incomplete are situated around the spinal cord.
They communicate with one another and above with the veins of cerebellum and the cranial venous sinuses.
Each artery of supply to the spinal cord has a corresponding vein
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The arteries of Adamkiewicz
Spinal branches from the 1st and 11th intercostal arteries – large
They pass along the nerve roots to the spinal cord and reinforce the anterior and posterior spinal arteries
Spinal artery at T1
supplies the cord only downwards
Spinal artery at T11
supplies the cord both above and below (radicularis magna)
