anatomy of spinal cord

1. @OSAMA_Z96
Video :
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2. 1- It begins superiorly at the foramen magnum in the skull
Foramen magnum

3. 2- The spinal cord Lies inside vertebral or spinal canal of the
vertebral column and protected by the parts of vertebrae.
- It Is surrounded by 3 layers called meninges :
A- The Dura mater.
B- The Arachnoid mater.
C- The Pia mater. Pia mater
Arachnoid mater
Dura mater

4. 3- Ages changes with the lower end of the spinal cord :
1- The spinal cord ends & terminates inferiorly in the adult at
the level of the lower border 1st lumbar vertebra at small
tapering part called the conus medullaris.
2- In the young child, it is ends at the upper border of the 3rd
lumbar vertebra.
3- Intrauterine, fill the whole length of vertebral canal.
Conus medullaris

5. 4- There are 2 enlargements are seen for the innervation of the upper
and lower limbs :
A- The Cervical enlargement :
Innervation the upper limbs extends from the 3rd cervical to
the 2nd thoracic segments (For brachial plexus).
B- The Lumbar enlargement :
Innervation of the lower limb from 1st lumbar to 3rd sacral
(For lumbosacral plexus).

6. 5- On cross sections of the spinal Segment
there are a central gray matter surrounded by white matter :
A- Gray matter :
Seen as an H-Shaped and It is formed of :
1- The anterior or ventral gray column (MOTOR).
2- The posterior or dorsal gray column (SENSORY).
B- White matter :
Is divided into 3 columns by external fissures :
1- Posterior funiculus or column.
2- Anterior funiculus column.
3- Lateral funiculus column : which contain lateral
spinothalamic tract that carry the ascending & sensory
pathway for pain & Temperature.
Gray mater
White matter
Gray mater
White matter
Anterior gray horn
(MOTOR)
Posterior gray horn
(SENSORY)
Anterior gray horn
(MOTOR)
Posterior gray horn
(SENSORY)

7. Gray mater
White mater
Anterior gray horn
(MOTOR)
Posterior gray horn
(SENSORY)

8. 6- When the nerve cells exits from the Anterior gray
column it called (Motor roots), and when it exits
from the Posterior gray column it called (Sensory roots).
- When the fibers mixed together it called (Spinal nerve).
Anterior gray horn
(MOTOR)
Posterior gray horn
(SENSORY)
Spinal cord segment
motor
rootlets
Sensory
rootlets
Spinal nerve
Dorsal root ganglion
Motor root
Sensory root

9. 7- When the spinal nerve passes through the
intervertebral foramen it divided to give pairs called :
Anterior & Posterior ramus,
and the anterior ramus is bigger than
the posterior ramus.
Anterior ramus
Posterior ramus
Spinal nerve
containing Sensory
& Motor fibers

10. 8- There are 31 spinal segments
which each part of them gives 1 pair of spinal nerve,
Thus there are 31 pairs of spinal nerves passes through
the intervertebral foramen.
- The spinal nerves passes from the intervertebral foramen as follow :
A) 8 Cervical pairs passes between the 7 cervical vertebrae.
B) 12 Thoracic pairs passes between the 12 thoracic vertebrae.
C) 5 Lumbar pairs passes between the 5 lumbar vertebrae.
D) 4 Sacral pairs passes through the 4 sacral foramen, Except
the 5th sacral pair, which passes through the sacral hiatus.
E) 1 Coccygeal pair passes through the sacral hiatus.
7 Cervical vertebrae
with 8 Cervical pairs
5 Lumbar vertebrae
with 5 Lumbar pairs
12 Thoracic vertebrae
with 12 Thoracic pairs
5 Sacral foramen contain 4 Sacral pairs,
& 1 Sacral foramen contain 1 Sacral pair & 1 Coccygeal pair

11. 9- The Filum terminale is a delicate strand of fibrous tissue,
proceeding downward from the apex of the conus medullaris.
- It is a continuation of pia mater.
- It is fix & support the spinal cord.
Filum Terminale

12. 3 Longitudinal arteries (arise from vertebral artery :
intracranial part ) & reinforced by many radicular arteries :
1- Anterior spinal artery (From vertebral artery).
2- Posterior spinal artery (From vertebral artery).
3- Radicular arteries (Branches from many arteries alongside
the vertebral column) :
- In Neck : from vertebral and ascending cervical arteries.
- In Thorax : from posterior intercostals arteries.
- In Abdomen : from lumbar arteries.
- In Pelvis : from sacral arteries.

13. * Origin :
Spinal cord originate from the posterior part of the Neural Tube.
* Congenital anomalies :
1- Spina bifida Occulta.
2- Spina bifida Cystica :
A) With Meningocele.
B) With Meningomyelocele.

14. Neural Tube