1. THE SPINAL CORD
SALVADOR S. BRILLANTES MD

2. Spinal Cord Function
 The Spinal Cord is a long, thin
bundle of nervous tissue and
support cells connected to the
brain and located along your
back and neck
 The spinal cord receives and
transmits electric signals
throughout the entire body and
then back to the brain
 The spinal cord is protected by
the vertebrae, which are bones
running down your back, and
also by cerebral spinal fluid,
which helps to cushion the
nerve tissue

3. EmBRYOLOGY & ANATOMY
 Neural tube
 18th gestational day
 Organization
 Butterfly shaped area of gray matter with surrounding white matter
 WHITE MATTER
 Consist mainly of longitudinal nerve fibers
 Ascending and Descending tracts
 GRAY MATTER
 Groups of nuclei

4. Anatomy
 The spinal column is divided into
four areas: Cervical, Thoracic,
Lumbar, and Sacral
 Each section contains nerves
that control certain muscles of
your body
 Each nerve has its corresponding
vertebrate, with the exception of
C8 which is located between the
C7 and the T1 vertebrates

5. Intervertebral Disc
 Intervertebral disc
• End plate
– Cartilaginous layer
– Bony layer
• Apophyseal ring

6. Intervertebral Disc
 Fibrocartilaginous joint of the
motion segment
 Make up ¼ the length of the
spinal column
 Present at levels C2-C3 to L5-S1
 Allows compressive, tensile,
and rotational motion
 Largest avascular structures in
the body

7. Intervertebral Disc
 Nucleus Pulposus Nucleus
Pulposus
– Inner structure
– Gelatinous
– High water content
– Resists axial forces

8. BLOOD SUPPLY OF SPINAL CORD
 ANTERIOR SPINAL ARTERY
 POSTERIOR SPINAL ARTERY
 RADICULAR ARTERIES
 THE GREAT RADICULAR
ARTERY OF ADAMKIEWICS

9. ARTERIAL SUPPLY: 3 LONGITUDINAL ARTERIES
1. One anterior spinal artery
• Supplies anterior 2/3’s of the cord
• Covers the length of the cord via the anterior
median fissure
2. Two posterior spinal arteries
• Supplies posterior 1/3 of the cord
• Anastomoses frequently with each other and
with anterior spinal artery
Note: these arteries are only enough to supply the
cervical region of the cord; remaining segments
get there blood supply from the radicular arteries

10. RADICULAR ARTERIES - BRANCHES FROM:
1. VERTEBRAL ARTERY
2. DEEP CERVICAL ARTERY
3. ASCENDING CERVICAL ARTERY
4. POSTERIOR INTERCOSTAL ARTERY
5. LUMBAR ARTERY
6. LATERAL SACRAL ARTERY
*ARTERY OF ADAMKIEWICZ
- Supplies thoracolumbar region and the
lumbosacral enlargement of the cord
- Usually left sided

11. Segmental Arteries
At each vertebral level from T4 to the sacrum, a pair
of SEGMENTAL ARTERIES branches posteriorly from
the aorta to supply blood to the vertebral body, posterior
elements, spinal cord, and costal structures.
Anterior spinal
artery
Spinal
branch
Posterior
branch
Intercostal
artery
Segmental
arteries
Anastomoses
Aorta

13. Venous drainage:
1. Distribution similar to arteries
2. 3 anterior and 3 posterior
spinal sinuses and veins
3. Internal vertebral plexus
• Thin walled and valveless
and surrounds dura mater
4. Path of drainage
• Anterior and posterior spinal
veins  venous plexus 
vertebral veins  ascending
lumbar veins  azygous veins

14. SPINAL CORD
1. Extends from foramen magnum of the occipital bone
2. 42-45 cm long
3. Adults L1-L2 disc
4. Occupies only the superior 2/3 of the canal

15. FIVE DIVISIONS OF SPINAL
CORD
1. CERVICAL
2. THORACIC
3. LUMBAR
4. SACRAL
5. COCCYGEAL
1.Enlargement over cervical area – C4-T1
•Forms the brachial plexus and
innervates upper extremit
2.Enlargement over lumbosacral area –
L2-S1
•Forms the lumbar and sacral plexus
and innervates the lower extremity

16. Spinal Nerve Structures
Spinal Cord Foramen
 Contained in epidural space magnum
 Network of sensory and motor
nerves
 Firm, cord-like structure
• Extends from foramen magnum to L1
• Terminates at the conus Conus
medularis medularis
• The cauda equina begins Cauda
below L1 equina
• Filum terminale extends from
conus medularis to the coccyx

17. INEQUALITY OF CORD VS
CANAL:
1. Length and obliquity of
the lower segments
increase due to
increased distance of
cord segments and
vertebral levels
2. Lumbosacral spinal
nerves are the longest
3. Conus medullaris –
tapers into the filum
terminale
4. Cauda equina

18. Meninges
Within the spinal canal, the spinal cord is surrounded by the
EPIDURAL SPACE, filled with fatty tissue, veins, and arteries. The fatty
tissue acts as a shock absorber.
The spinal cord is covered by MENINGES which has three layers.
Pia mater Subarachnoid
space: filled
with CSF
Subdural space
Arachnoid
layer
Dura mater

19. Dura Mater
•Outer most covering
•Long tubular sheath
•Forms dural root sleeve as nerve
exits foramen
Arachnoid Mater
•Avascular intermediate
•Potential space separates it from the
dura mater
Pia Mater
•Innermost covering
•Adheres to spinal cord

20. LAYERS:
1. Extra dural space – fat loose connective tissue; anterior
and posterior plexus of vessels
2. Dura mater
3. Subdural space – only contains a potential space
4. Arachnoid mater
5. Subarachnoid space – CSF and vessels
6. Pia mater

21. Spinal Nerves
Spinal Epidural
cord space
Dura mater and
Arachnoid layers
Dorsal root
Subarachnoid
space
Dorsal root
ganglion
Ventral Peripheral
root nerve

22. SPINAL CORD DIVISIONS

23. Laminae of Rexed - groupings
 Laminae I – VI located in the posterior horn
 Lamina VII  located at the lateral horn
 Laminae VIII and IX  located at the anterior horn
 Lamina X  gray substance surrounding the central canal

25. -Malmon MD

26. Thank you!
“Out of difficulties…grow miracles’ – malmon buddy