Arterial Supply And Venous Drainage Flashcards
From what arteries does the main blood supply to the cervical vertebrae arise?
Vertebral arteries
Ascending cervical arteries
Where do the vertebral arteries originate?
Subclavian arteries (as the V1 segment)
What is the relations of the V2 segment of the vertebral artery within the C6 transverse foramen?
Anterior to nerve roots
Covered by intertransversarii
Accompanied by SNS plexus from inferior cervical ganglion
Surrounded by venous plexus (vertebral vein)
What is the reference for the course of the vertebral artery itself?
Campero et al., 2011
What do the anterior branches of the vertebral arteries supply?
Ventral surface of cervical vertebral bodies (by directly penetrating cortical bone)
Uncovertebral joints
At what levels do the anterior branches of the vertebral arteries most commonly arise?
C3 and C4
What special anterior branch of the vertebral artery arises at C2? What does it supply?
Anterior ascending branch
Supplies:
- Ventral body of C2
- Dens
What is the alternate name for the posterior branches of the vertebral arteries?
Post-laminar arteries
What do the posterior branches of the vertebral arteries supply?
Dorsal surface of cervical laminae
Spinous processes
Where do the posterior branches of the vertebral arteries most commonly arises?
C4 and C5
What do the lateral branches of the vertebral arteries supply?
Mostly supply deep neck musculature
Osteoarticular branches supply facet joints
What is the course of the anterior part of the medial branches of the vertebral arteries?
Runs deep to PLL and anastomoses with its contralateral counterpart
What does the anterior part of the medial branch of the vertebral artery supply?
Main bloody supply to vertebral body:
- Enters dorsal surface
- Single nutrient vessel enters in midline and penetrates to half of vertebral body depth
What pattern does the posterior part of the medial branch of the vertebral artery form and what does it supply?
Arcuate pattern on posterior aspect of spinal canal Supplies: - Lamina - Spinous process - Pedicles - Facet joints
What is the alternate name for the medial branches of the vertebral arteries and why?
Lateral spinal branches
They enter the spinal canal from its lateral aspects via IV foramina
What is the main reference for the branches of the vertebral arteries?
Özgen et al., 2004
What are the common origins of the ascending cervical arteries? (Reference?)
Inferior thyroid artery (72.3%)
Thyrocervical trunk (10.7%)
(Daseler et al., 1959)
How do the ascending cervical arteries supply the vertebral column? What do they supply?
Give off Spinal branches that enter spinal canal via IV foramina Supply: - Spinal Cord and meninges (mainly) - Dorsal edges of vertebral bodies - Ventral laminae
What other branch of the vertebral artery supplies the spinal canal? Where does it arise?
Osseous branches of the anterior meningeal branch
Arises from medial surface of vertebral artery above C3 transverse foramen
Supplies:
- Body and dens of C2
- Articular plate of atlanto-occipital and atlantoaxial joints
What is the reference for the anterior meningeal branch?
Campero et al., 2011
From what arteries does the arterial supply to the thoracic vertebral column arise?
Posterior intercostal arteries
As the posterior intercostal arteries cross the anterolateral aspects of the thoracic vertebral bodies, what branches supply these aspects?
Periosteal branches -> Lie on and supply surface
Equatorial branches -> Penetrate cortical bone and supply ventral vertebral bodies
At what level do the spinal branches of the posterior intercostal arteries enter the spinal canal?
At the level of the costotransverse joints
What do the spinal branches of the posterior intercostal arteries supply?
Anterior branch -> Dorsal aspect of vertebral body
Posterior branch -> Ventral aspect of lamina
From where does the blood supply to the lumbar vertebral column arise?
Lumbar arteries
What do the posterior spinal canal branches of the lumbar arteries supply? (Reference?)
Epidural fat Dural sac Base of spinal processes Lamina: - The branch to these also supplies both the superior and inferior articular facets (Bogduk, 2005)
Where do the lumbar arteries arise?
4 pairs from posterolateral abdominal aorta
5th pair from middle sacral artery
Where do the primary periosteal arteries arise?
From superior and inferior surfaces of lumbar arteries
How many primary periosteal arteries arise from each lumbar artery?
10-20 per lumbar artery
What anastomosis do the most posterior pairs of primary periosteal arteries form?
Precostal anastomosis
Where do the metaphyseal arteries lie?
In the upper and lower metaphyses of each vertebral bodies
In what plane do the metaphyseal arteries run and what arteries may join them?
Run horizontally
Primary periosteal arteries join them
In what individuals are the secondary periosteal arteries more marked?
Elderly
What do the spinal branches of the lumbar arteries hook over?
The lateral aspect of PLL
What branches do the spinal arteries from the lumbar arteries give off? What is the course of these branches?
Ascending and descending branches:
- May anastomose with those on adjacent vertebrae
- May anastomose with contralateral side = Post-central anastomosis
What two diagrams are important for understanding the arterial supply to the lumbar vertebrae?
Ratcliffe, 1980
Bogduk, 2005
What arteries give branches to supply the sacrum?
Iliolumbar arteries
Lateral sacral arteries
Median sacral artery
Where do the iliolumbar arteries arise from?
Usually from posterior trunk of the internal iliac artery
May arise directly from posterior aspect of internal iliac artery
Where do the iliolumbar arteries run in relation to the SIJs?
Superolaterally in front of the SIJs
A lumbar branch of the iliolumbar arteries can anastomose with which artery?
4th lumbar artery
Describe the spinal branch of the iliolumbar artery?
Small
Enters spinal canal via IV foramen between L5 and S1
What is the reference for the iliolumbar arteries?
Teli et al., 2013
Where do the lateral sacral arteries arise?
A superior and inferior branch on each side from the posterior aspect of the internal iliac arteries
What is the course of the lateral sacral arteries?
Pass medially
Descend anterior to sacral ventral rami
Describe the spinal branches of the lateral sacral arteries
Pass through anterior sacral foramina
Supply vertebrae similarly to other spinal branches
Where does the median sacral artery arise?
An unpaired branch from the posterior aspect of the abdominal aorta prior to bifurcation
What is the course of the median sacral artery?
Runs anterior to:
- L4 and L5
- Sacrum
- Coccyx
Where does the median sacral artery give off branches and what do they do?
Anterior to sacrum:
- Anastomose with lateral sacral arteries and support the spinal branches
How does the median sacral artery supply the anterior sacrum?
Small periosteal and equatorial branches
Why are IV discs avascular?
The blood vessels surrounding them during early development gradually regress
What parts of the vertebral bodies are vascular and avascular?
Vascular = More central parts Avascular = Part of VB immediately adjacent to IV disc
The central vascular region of a vertebral body can be divided into 3 parts. What are these?
Part supplied by nutrient artery Part supplied by metaphyseal artery Part supplied by peripheral arteries: - Equatorial - (Secondary) periosteal
Why does the zoning of blood supply to the vertebral bodies arise?
Probably due to arrangement of IV disc annulus fibres dictating where diffusion of oxygen and nutrients is required
Where do mature IV discs rely on diffusion of nutrients from?
Vertebral endplate
How are the IV discs supplied with nutrients?
- Vertebral endplates act as semipermeable membranes for exchange of nutrients into lamellae of annulus fibres
- Fluid trapped between lamellae and moves in the vertical plane
- Frequent fluid movement -> Speeds up diffusion
As we age, the lumens of arteries narrow. What arteries are affected first and what are examples of these in the vertebral column? (Reference?)
Tortuous arteries affected first:
- Nutrient arteries
- Metaphyseal arteries
(Palastanga and Soames, 2012)
Why does the nucleus pulposus dehydrate and lose its elastic properties with age? (References?)
Loses proteoglycans and gains collagen (Moore and Dalley, 2006)
- Results in loss of glycosaminoglycans
- Reduced osmotic pressure of disc matrix
- Loss of hydration (Urban and Roberts, 2003)
What happens when the nucleus pulposus dehydrates and becomes inelastic?
IV disc stiffening:
- Loses ability to deform and reform under pressure
- When load is applied it loses height
When and where can the first signs of IV disc degeneration be seen?
In lumbar discs of 11-16 year olds
What percentage of teenagers have mild IV disc degeneration?
20%
In what individuals is there a steeper increase in prevalence of IV disc degeneration with age?
Males