Bllod Supply Of The Spinal Cird

Question 1

What is the artery supply of the spinal cord

Answer 1

The spinal cord is supplied by three sets of artery
1-Two longitudinal artery (Anterior an Posterior spinal arteries
2-Many radicular segmental arteries

Question 2

Discuss the anterior spinal artery
(Origin-course-Distribution)

Answer 2

Origin: A single artery that is formed by union of two anterior spinal arteries, each is a branch of the vertebral artery inside the skull

Course: it descend through the foremen magnum and then runs in the anterior median fissure of the spinal cord

Ditribution: it supplied the medial part of medulla oblongata and the 2/3 of cross sectional area of the spinal cord ie anterior and lateral white column, ventral horn and lateral horn and base of dorsal horn

Question 3

Discuss the posterior spinal artery
(Origin-Course-Distribution)

Answer 3

Origin: Each posterior spinal artery arises from vertebral artery or most commonly from posterior inferior cerebellar artery branch

Course: it descends through the foremen magnum then along the postro lateral sulcus dividing into two branches one descend anterior and the other posterior to the dorsal roots of the spinal cord

Distribution: it supplied the posterior 1/3 of the spinal cord : posterior white column and dorsal horn

Question 4

Discuss segmental arteries

Answer 4

Origin : arise as twigs from vertebral, ascending cervical, posterior intercostal, and 1st lumber

Course:
-the enter the vertebral canal through the intervertebral foremen
-The give anterior and posterior branches that pass along the central and dorsal roots to reach the surface of the spinal cord, form an arterial circle of anastomosis with anterior and posterior spinal arteries “arterial vasa corona”
-branches from this circle supply the periphery of the spinal cord

Question 5

What are large radicular artery called?
Mention one of them

Answer 5

Feeder arteries
One of the feeder arteries are artery of Adamkiewicz which arises from the 11tg intercostal artery and may be the main supply of the lower 2 thirds of spinal cord

Question 6

What do different parts of spinal cord depends on
Which segment has the richest blood supply
And which parts are more liable to ischemia

Answer 6

The cervical part depends more on anterior and posterior spinal while the lower segment depends more radicular arteries
The lumber region has the richest blood supply
The mid-thoracic segments are more liable to injury

Question 7

Mention the veins supplying the spinal cord

Answer 7

Six longitudinal veins ascend along the spinal cord:
-anterimedian vein along the anterior median fissure
-posterimedian vein along the posterior median spinal vein
-Four veins that run on either sides of ventral dorsal root

Question 8

What is the course of venous drainage of the spinal cord

Answer 8

The veins communicate freely with each other , drain into internal venous plexus and communicate with the intervertebral veins
Near the skull, the longitudinal veins communicate with cerebellar vein and cranial venous plexus

Question 9

What are the effects of hemisection of the cord

Answer 9

1-at the same level of lesion
Ipsilateral loss of sensations (destruction of posterior root)
Ipsilateral LMNL(damage of ant. horn cells)
2-below the lesion
Ipsilateral loss of proprioceptive sensations (affection of posterior column)
UMNL( affection of lateral corticospinal tract)
Contralateral loss of pain and temperature ;affection of lateral spinothalaminc tract)

Question 10

What are the effect of anterior spinal artery occlusion

Answer 10

-Bilateral UMNL paralysis below the lesion
-Bilateral loss of pain and temperature sensation below the lesion with preservation of proprioception and fine touch