The vertebral canal contains the spinal cord, spinal nerve roots, spinal meninges, and neurovascular structures. The spinal cord begins in the foramen magnum and ends between L1-L2, protected by vertebrae and other structures. It has 31 segments and two enlargements. Spinal nerve roots exit through intervertebral foramina. The spinal meninges (dura mater, arachnoid mater, pia mater) cover and protect the spinal cord, suspended in cerebrospinal fluid. The spinal cord receives blood supply from the anterior/posterior spinal arteries and segmental medullary arteries.

1. CONTENTS OF VERTEBRAL
CANAL
B Y ; O M E R A S L A N K A N

2. THE VERTEBRAL
CANAL CONTAINS
• Spinal cord
• Spinal nerve roots
• Spinal meninges
• Neurovascular structure

3. SPINAL CORD
• begins at the foramen magnum and terminates between the 1st
and 2nd lumbar vertebrae.
• The tapered end of the spinal cord is called the conus
medullaris.
• There are 31 spinal cord segments: 8 cervical, 12 thoracic, 5
lumbar, 5 sacral, and 1 coccygeal
• spinal cord is 42–45 cm long.
• Is protected by The vertebra, muscles, ligaments, spinal
meninges and CSF
• Has 2 regions of enlargement;
• 1) cervical enlargement; spans the C4 through T1 segments
anterior rami from most form the brachial plexus - innervates
upper limb
• 2) lumbosacral enlargement; spans the T11 through S1
segments. and anterior rami becomes lumbar and sacral
plexus that innervate lower limbs

4. SPINAL NERVE ROOTS
• The spinal nerve roots go from the spinal cord segments to
their opening - it is an intervertebral foramen.
• Just before reaching the opening, the roots join to form a spinal
nerve and then exit the vertebral canal.
• The C1 spinal nerve exits above the arch of the C1 vertebra.
• Nerves C2 to C7 exit through the intervertebral foramina
superior to their corresponding vertebra.
• The C8 spinal nerve exits through the intervertebral foramen
between the C7 and the T1 vertebrae.
• Nerves T1 to L5 then exit through intervertebral foramina
inferior to their corresponding vertebra.
• S1-S4 branch pass through anterior and posterior sacral
foramen
• S5 and Co1 nerves pass through sacral hiatus
• The collection of nerves at the end of the spinal cord is known
as the cauda equina.

5. SPINAL MENINGES
• The spinal cord and the spinal nerve roots are covered by three
membranes collectively called the spinal meninges: the spinal
dura mater, arachnoid mater, and pia mater.
• The spinal meninges are continuous with the cranial meninges
through the foramen magnum and they function to support
and protect the spinal cord.
• They also contain the cerebrospinal fluid, or CSF for short, in
which the spinal cord is suspended.
• The dura mater is separated from the bony walls of the
vertebral canal by the epidural space and forms the dural sac (is
innervated the meningeal nerves) (It is fibrous layer)
• The spinal arachnoid mater is pressed against the dura by the
cerebrospinal fluid of the subarachnoid space. (Contains the
spinal cord, spinal nerve roots, CSF and spinal ganglia)
• The spinal pia mater directly covers the spinal cord, the spinal
nerve roots, and spinal blood vessels. Inferior to the spinal cord,
it continues as a fine thread called the filum terminale.(it is
vascular layer)

6. NEUROVASCULAR ARTERIES
• The blood supply for the spinal cord comes from a few sources.
• First, there are three longitudinal arteries: one anterior spinal artery
and two posterior spinal arteries.
• The anterior spinal artery originates within the cranium from
of the vertebral arteries.
• The two posterior spinal arteries also originate in the cranium either
branches of the vertebral arteries or the posterior inferior cerebellar
arteries.
• The three longitudinal arteries can only supply the superior part of
spinal cord by themselves.
• The posterior and anterior segmental medullary arteries arise at
vertebral levels from the spinal branches of the ascending cervical,
deep cervical, vertebral, posterior intercostal, and lumbar arteries.
• Great anterior segmental medullary artery also reinforces the blood
supply to the lower two-thirds of the spinal cord.
• Unlike the segmental arteries, they do not anastomose with the
anterior and posterior spinal arteries.

7. NEUROVASCULAR VEINS
• The veins of the spinal cord usually follow the arteries.
• There are typically three anterior and three posterior
spinal veins.
• They drain into anterior and posterior medullary and
radicular veins, which communicate with the epidural
venous plexus.
• From the epidural venous plexus, blood flows to the
dural sinuses of the cranium, the vertebral veins, and
the external vertebral venous plexuses.

8. CONCLUSION
• The spinal cord has 31 spinal segments and pairs of spinal nerves: 8
cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal.
• The two enlargements of the spinal cord are the cervical enlargement
and lumbosacral enlargement.
• The spinal cord and the spinal nerve roots are covered by the spinal
meninges, which consist of the dura mater, arachnoid mater, and pia
mater.
• The dura mater is separated from the bony walls of the vertebral canal
the epidural space.
• The spinal arachnoid mater is pressed against the dura by the
cerebrospinal fluid of the subarachnoid space.
• The spinal pia mater directly covers the spinal cord, the spinal nerve
roots, and spinal blood vessels. Inferior to the spinal cord, it continues as
a fine thread called the filum terminale.
• Laterally the spinal pia mater forms extensions along the spinal cord
called the denticulate ligaments.
• the spinal cord blood supply comes from the anterior spinal artery, the
two posterior spinal arteries, and the posterior and anterior segmental
medullary arteries, including the great anterior segmental medullary
artery.
• Venous blood drains through three anterior spinal veins and three
posterior spinal veins.

9. REFERENCES
• Dr. Victor .C.Okika PPTX
• Clinically oriented anatomy 6th edition
• Wkipedia
• https://healthjade.com/spinal-cord/
• https://www.researchgate.net/figure/Spinal-venous-anatomy-
11_fig3_328107614

10. THANK YOU