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Last edited: 8/13/2021

1. SPINAL CORD BLOOD SUPPLY

Neurology | Spinal Cord Blood Supply Medical Editor: Dr. Sarah Abimhamed

OUTLINE

I) MAIN BRANCHES THAT SUPPLY SPINAL CORD

II) ARTERIES OF THE OF THE SPINAL CORD
III) CLINICAL CORRELATION
III) APPENDIX (D) RECALL - BRANCHES OF SUBCLAVIAN ARTERY:
IV) REVIEW QUESTIONS
V) REFERENCES 3 parts of subclavian artery:
The parts are split up by anterior scalene muscle.
The first part is medial to the muscle, the second is
posterior to it, and the third is lateral to it [Moore, Essential Clinical
Anatomy]
I) MAIN BRANCHES THAT SUPPLY SPINAL CORD I) Medial to the anterior scalene: vertebral artery
The main branches that supply the spinal cord and their II) Posterior to the anterior scalene: costo-cervical
divisions, according to different regions trunk which branches into deep cervical and
AfraTafreeh.com supreme intercostal branch
(A) UPPER PART OF THE SPINAL CORD III) Lateral to the anterior scalene: dorsal scapular
Supplied by: Left subclavian artery [Moore, Essential Clinical Anatomy]
- Which branches into:
→ Vertebral Artery
→ Deep Cervical Artery

(B) MIDDLE & POSTERIOR PART OF THE SPINAL CORD

Supplied by: Thoracic aorta,
- Which branches into:
→ Posterior Intercostal Arteries

(C) LOWER PART OF SPINAL CORD

Supplied by: Abdominal aorta
- Which branches into:
→ Lumbar Arteries
→ Lateral Sacral Arteries
Figure 2. Division of the Subclavian Artery

II) ARTERIES OF THE OF THE SPINAL CORD

(A) VERTEBRAL ARTERIES

The arteries of the spinal cord run longitudinally from the

medulla of the brainstem to the conus medullaris of the
spinal cord. [Essential Clinical Anatomy]

There is one that runs anterior called the anterior spinal

artery (ASA), and a pair of arteries running posteriorly
called the posterior spinal artery (PSA).

There are 3 main branches that supply the spinal cord:

Arteries of spinal cord Origin Supply
Anterior 2/3 of
Anterior spinal artery Vertebral artery
spinal cord
Vertebral artery or Posterior 1/3 of
Pair of posterior spinal
posterior inferior spinal cord
arteries
Figure 1. Main arteries that supply the spinal cord cerebellar artery

Table 1. Branches of the Vertabral Arteries

(B) POSTERIOR INTERCOSTAL ARTERIES

Posterior intercostal arteries branch into anterior and
posterior radicular arteries which supply ASA and PSA,
respectively.
The radicular arteries also provide vascular supply for the
nerve roots along which they track.

Spinal cord blood supply NEURO PHYSIOLOGY: Note #1. 1 of 3

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CLINICAL PRESENTATION:
These are all the result of damage to the anterior 2/3 of the
spinal cord. (See Table 3. Summary of Clinical Presentation
of ASA Syndrome)
(1) Paraplegia
Anterior grey horn contains nerve
supply to the somatic nervous
system  paralysis of skeletal
muscles of lower extremities (type of
Figure 3. Division of Posterior Intercostal Arteries
paraplegia)

Origin & Division of the Posterior Intercostal Arteries

Origin 1st Division 2nd Division 3rd Division
Anterior Anterior spinal artery Figure 5. Skeletal Muscle
radicular supplied by somatic nervous
Spinal artery system
branch of
Aorta posterior
intercostal Posterior Posterior spinal artery (2) Urinary and Fecal Overflowing/Incontinence
artery radicular
artery
AfraTafreeh.com Intermediomedial nuclei located in the anterior 2/3 of the
spinal cord, this nuclei is part of the parasympathetic
Table 2. Branches of Posterior Intercostal Arteries system. This results in:

Vasa corona: connection between the anterior and a. Detrusor muscle is not
posterior spinal artery getting proper nerve
supply, so cannot
Around T10-12, lumbar and sacral region, the main blood contract, it can overfill 
supply that feeds into anterior spinal artery is the artery of overflowing continence
Adamkiewicz (also called great anterior segmental
medullary artery).

Figure 6.Bladder overfilling due

III) CLINICAL CORRELATION
to lack of proper nerve supply to
detrusor muscle & lack of
ANTERIOR SPINAL ARTERY SYNDROME function of internal urinary
Anterior Spinal Artery Syndrome sphincter

This occurs when the anterior spinal artery is not getting

enough blood supply due to damage, occlusion, emboli,
b. Parasympathetic nerve
etc. of the artery of Adamkiewicz. This affects the anterior
supplies the smooth
2/3 of the spinal cord.
muscles of the sigmoid
colon  unable to
Note: affected area is the T10-T12 and lumbosacral region
contract and excreted
as that is the area where the ASA receives blood supply
feces therefore sigmoid
from artery of Adamkiewicz. (See Figure 3)
colon starts distending 
overflowing causes fecal
incontinence

c. Neurons also supply

internal (involuntary)
urinary and fecal
sphincters  urinary and
fecal incontinence
Figure 7. Sigmoid colon distending due to
lack of proper nerve supply, it affects
internal fecal sphincter to leading to fecal
incontinence

(3) Motor paralysis and loss of reflexes

Descending motor nerve fibers are affected. They start
from the cerebral cortex that terminates on lower motor
neurons and interneurons in the spinal cord, controlling
movements of the limbs and trunk [Fundamentals of human
neuropsychology]

Figure 4. Area of the spinal cord affected in ASA Syndrome (4) Bilateral loss of pain and temperature
Anterolateral spinothalamic tract is found in the anterior
2/3 of the spinal cord  it carries pain temperature and
crude touch sensation. Therefore, in ASA syndrome there
is bilateral loss of pain and temperature sensation.

2 of 3 NEURO PHYSIOLOGY: Note #1. Spinal cord blood supply

 IV) III) APPENDIX

Area affected Result of the damage Reason for the damage

Anterior grey horn (somatic Paralysis of skeletal muscles of lower Anterior grey horn is located in the anterior 2/3 of the
Anterior Spinal Artery Syndrome

nervous system) extremities (type of paraplegia) spinal cord and contains nerve supply to the somatic
nervous system which controls the skeletal muscles
Urinary overflowing continence Detrusor muscle of the bladder does not get proper
nerve supply, so it cannot contract  overfills
Neurons also supply internal (involuntary) urinary
Intermediomedial nucleus
sphincters
(parasympathetic nervous
Fecal incontinence Parasympathetic nerve muscles supply smooth
system)
muscle of the sigmoid colon
Neurons also supply internal (involuntary) fecal
sphincters AfraTafreeh.com
Anterolateral spinothalamic Bilateral loss of pain and temperature Anterolateral spinothalamic tract carries pain
tract sensation temperature and crude touch sensation
Descending autonomic fibers Motor paralysis and loss of reflexes The descending nerve fibers control movements of the
limbs and trunk

Table 3. Summary of Clinical Presentation of ASA Syndrome

a. Lack of blood supply to the intermediomedial nuclei

V) REVIEW QUESTIONS b. Damage to the parasympathetic nervous system
c. Lack of blood supply to the skeletal muscles
Which artery supplies the vertebral arteries?
d. Lack of blood supply to the anterior grey horn
a. Deep cervical artery
b. Left subclavian artery
What does lack of blood supply to the anterolateral
c. Brachiocephalic trunk
spinothalamic tract cause?
d. Posterior intercostal artery
a. Unilateral loss of pain
b. Bilateral loss of temperature and pain
What is the origin of the posterior intercostal artery?
c. Unilateral loss of temperature
a. Subclavian artery
AfraTafreeh.com d. Bilateral loss of pain
b. Deep cervical artery
c. Thoracic Aorta
Which nervous system is affected in urinary
d. Lumbar artery
incontinence due to detrusor muscle not being able to
contract?
What is the origin of anterior and posterior radicular
a. Sympathetic nervous system
arteries?
b. Paraysmpathetic nervous system
a. Abdominal aorta
c. Somatic Nervous system
b. Spinal branch of posterior intercostal muscle
d. Intermediomedial nucleus
c. Vertebral Arteries
d. Costocervical trunk
Which part of the colon is affected in ASA
syndrome?
Which artery of the spinal cord runs longitudinally
a. Transverse Colon
and posteriorly from the medulla of the brainstem to
b. Ascending Colon
the conus medullaris of the spinal cord?
c. Sigmoid Colon
a. Anterior radicular artery
d. Descending Colon
b. Posterior radicular artery
c. Anterior and Posterior Spinal Arteries CHECK YOUR ANSWERS
d. Posterior Spinal Arteries
VI) REFERENCES
Which areas of the spinal cord does the anterior Moore, K. L., MD, Agur, A. M. R., PhD, & Dalley, A. F., II. (2014).
spinal artery supply? Moore Essential Clinical Anatomy (5th ed.). Lippincott Williams &
a. Anterior 2/3 of the spinal cord Wilkins.
b. Anterior 1/3 of the spinal cord Gofur, E. M. (2020, July 27). Anatomy, Back, Vertebral Canal
c. Nerve roots Blood Supply - StatPearls - NCBI Bookshelf. NCBI.
d. Anterior ½ of the spinal cord https://www.ncbi.nlm.nih.gov/books/NBK541083/#article-
36647.s11

Which artery supplies the anterior spinal artery at Kolb, B. & Whishaw, I. Q. (2009). Fundamentals of human
the T10-T12 and lumbosacral region? neuropsychology: Sixth edition. New York, NY: Worth Publishers.
a. Anterior segmental artery
b. Posterior Intercostal Artery
c. Artery of Adamkiewicz
d. Artery of Adam of Kiewicz

What is the cause of paraplegia of the lower

extremities in Anterior Spinal Artery Syndrome?

Spinal cord blood supply NEURO PHYSIOLOGY: Note #1. 3 of 3