Gross Topography of the Spinal Cord Flashcards
What essentially is the spinal cord?
A conduction pathway for nerves and nerve impulses located within the vertebral column
What protects the spinal cord?
Vertebrae, muscles, ligaments, meninges, and CSF
Where does the spinal cord extend from?
The pyramidal decussation to L2
What is the pyrimidial decussation?
Decussation means “crossing” - it is at the level of the medulla and the foramen magnum
What is the lumbar cistern?
The area between the end of the spinal cord - L2
Where is the dural sac?
Level S2
What is the filum terminale?
Where the spinal cord is attached all the way down to the coccyx, this is to maintain integrity and prevent movement of the spinal cord
What are the primary curvatures?
Thoracic and sacral
What are the secondary curvatures?
Cervical and lumbosaccral
When do the secondary curvatures develop?
When you are a baby, these develop as baby gains mobility
Why is differential growth important?
Because the vertebral column grows faster than the spinal cord, so for a new born, the bottom of the spinal cord is located around L2-L3 (lower) than for an adult where it is always at L2
Why is the spinal cord said to be “segmenta;”
because it is made up of 31 pairs of spinal nerves
What are the spinal nerves
Cervical - 8 Thoracic - 12 Lumbar - 5 Saccral - 5 Coccygeal - 1
Where do the spinal nerves exit?
C1-C7 exit above the vertebrae of the same number, but C8 and below exit blow the vertebral body of the same number
What is the conus medullaris?
Where the spinal cord ends and forms a “v”
What is the cauda quina?
Group of spinal nerve roots, said to look like a horse tail
What is the filum terminale?
A little piece of conus medullaris that attaches to the coccyx, The outside is dura and the inside is pia, it is said to be a “tethered cord” and the internis is 2/3 of the total volume whereas the externis is 1/3
“pia encased in dura”
Denticulate ligaments?
keep spinal cord from moving too much, located inside the dura, made of pia, serated in shape
What is tethered cord syndrome?
Filum terminale is too tight and prevents any movement at all, can cause permanent damage to the spinal cord, caused by disturbed or improper growth of neural tube, spina bifida, and or trauma
What is the dorsal rootlet?
Small, fine, thin structures that coalesce to form the dorsal root, such as the dorsal root ganglia
What is the dorsal root?
Sensory
What is the ventral root?
Motor
What happens after the dorsal root ganglia?
The spinal nerves become mixed nerves
How are spinal nerves different from dermatomes?
Spinal nerves are associated with a specific somite; cutaneous distribution is mixing spinal nerves, and a dermatome is strictly one spinal nerve for each area
1 somite per spinal nerve
