VASCULARIZATIO
N OF VERTEBRA
Chapter 1
Introduction
■ Function of vertebrae
– Protect spinal cord, nerve root
– Weight bearer
■ Vertebra
– 7 bones of cervical
– 12 bones of thoracic
– 5 bones of lumbal
– 5 bones of sacral
CHAPTER II
LITERARY REVIEW
Artery
■ Aorta
■ Subclavian a.
■ Vertebral a.
■ Anterior spinal a.
■ Spinal segmental a.
■ Posterior spinal a.
Aorta
Aorta branch out into 3 arteries.
The right side would branch out
into brachiocephalic a. and the left
side would be left subclavian a. and
left common carotid a.
Brachiocephalic a. branch out into
2 arteries:
Right common carotid a.
Right subclavian a.
Subclavian a.
■ Divided into 3 parts:
– First part
– Second part
– Third part
■ Subclavian a. branch out into:
– vertebral a.
– Thyrocervical a.
– Cervicalis ascendens a.
Vertebral a.
■ Divided into 4 pars:
– Pars prevertebralis: C7-C6
– Pars transversaria: C6-C2
– Pars atlantica: C2-C1
– Pars intracranialis: turn dorsal and upward on the posterior arch of processus
spinosus C1
■ Vertebral a. lies upward and branch
out into posterior inferior cerebellar
a. and at pons would join into basilar
a.
■ Vertebral a. branch down and become
anterior spinal a. and posterior spinal
a.
■ The most common disease in this
artery is thrombosis and dissection
Vertebral Artery Thrombosis
■ Thrombosis in vertebral a. caused by
plaque made of cholesterol or
calcium and the most common is
caused by dissection. This lesion
would make brain’s blood flow
decrease or block the blood flow
■ Thrombosis increase the risk of
transient ischemic attack (TIA) or
stroke
Vertebral Artery Dissection (VAD)
■ VAD is tearing of tunica intima (inner
layer) causing the blood to flow
through tunica media and clotting
causing insufficiency of blood flow
■ Usually happen in pars prevertebralis
and transversaria
■ The symptom is stroke-like symptom
(headache, loss of balance, visual
loss)
Bow Hunter’s Syndrome
■ Definition: insufficiency
vertebrobasilar caused by dynamic
compression of vertebral artery
■ This syndrome is very rare
Vertebral Artery Ectasia
■ Definition: abnormal dilatation of
vertebral artery
■ Caused by wall thinning and
elongating (aged factor related) or
occlusion of carotid a. and vertebral
a. compensate to maintain brain
perfusion
Anterior spinal a.
■ Anterior spinal a. lies downward
from C1 to cauda equina
■ It receives blood from medullaris
segmentalis a.
Anterior Spinal Cord syndrome
■ Caused by compression in anterior
spinal artery that results in anterior
cord ischemia or direct compression
of anterior cord
■ Symptoms: loss of motoric function,
loss of temperature and pain
perception
Spinal segmental a.
■ Aorta branch out into posterior
intercostalis a., this branch then
branch out into spinal segmental a.
■ Spinal segmental a. branch out into:
– Medullaris segmentalis a.
– Anterior radicular r.
– Posterior radicular r.
■ The biggest medullaris segmentalis a.
is artery of adamkiewicz
Artery of adamkiewicz
■ The biggest medullaris segmentalis a.
■ Supply the 2/3 posterior of vertebrae
■ The most common disease happen in this artery: spondylitis TB
Spondylitis TB
■ Definition: TB outside the lungs that
occur in the vertebrae
■ The most common areas got infected
are lower thoracic and upper lumbar
■ The infection spread to the
interbertebral disc space. Oxygen
would then be used by the bactery
causing caseous necrosis where the
disc tissue dies leading to vertebral
narrowing and eventually vertebral
collapse
Posterior spinal a.
■ Receives blood from posterior
radicular r.
■ It forms plexus called arterial
vasocorona
Venous drainage
■ Venous system:
– Intrinsic system
– Extrinsic system
– Extradural system
Intrinsic
■ Medial capillaries ventral & dorsal
sulcal v.
■ Peripheral capillaries radial veins
form venous ring
Extrinsic
■ Pial venous network
– Receive drainage from sulcal v.
■ Longitudinally oriented extrinsic venous system
– Dorsal median v. receive blood from radial v. & venous ring
■ Radicular v. (radiculomedullary v.)
– Connect extrinsic & extradural system
– Receives blood from ventral & dorsal median v.
– Drain into extradural vertebral venous plexus
Extradural
■ Vertebral venous plexus / Batson’s plexus
– Internal Connected by
– External intervertebral veins
– Basivertebral connected with ant. Internal vertebral venous plexus
■ Extraspinal efferent
– Cervical vertebral
deep cervical sup. Vena cava
jugular v.
– Thoracic
■ Right intervertebral v. azygos v.
Sup. Vena cava
■ Left intervertebral v. hemiazygos v. azygos v.
– Lumbosacral
■ Ascending lumbar v. inf. Vena cava
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