1. Spinal Cord Cross Section

2. The Spinal Cord Main Functions:
Transmission of neural signals between brain and rest of body
Contains neural circuits that can independently control reflexes

3. Grey Matter The darker tissue of the brain and spinal cord
Consists mainly of nerve cell bodies and branching dendrites
Includes regions of the brain involved in muscle control, emotions, speech, decision making, and self-control
95% of all the oxygen that goes into the brain goes into the grey matter

4. White Matter
The paler tissue of the brain & spinal cord, consisting mainly of nerve fibers with their myelin sheath
CNS
No dendrites (unlink grey matter)
Transmits signals from one region of the cerebrum to another
The “wiring” of the spinal cord; carries information
Computer Analogy:
Grey matter = the actual computer
White matter = network cables connecting the computers together

5. Central Canal AKA “ependymal canal”
Cerebrospinal fluid-filled space that runs up and down the length of the entire spinal cord
Continuous with the ventricular system of the brain
Represents the remainder of the central cavity of the neural tube (the embryo’s precursor to the CNS)
Eventually closes off with age

6. Spinal Nerve
There are main bundles of fibers that branch off the spinal cord and goes to other areas of the body
Carries signals of sensation
A pair of these spinal nerves branch out from each level of the spinal cord

7. Dorsal & Ventral Roots
At the innermost base of each spinal nerve root there are 2 sub-roots that connect the nerve to white and grey matter:
The dorsal nerve root: receives sensory (or touch) signals and carries them to the brain (afferent)
Ventral nerve root: ventral root sends out signals of movement from the brain to the body (efferent)

8. Important Info About The Dorsal Nerve Root
Controls pain and temperature sensations
If severed, pinched, or constricted, the signals of dorsal nerve root will be intensified or interrupted
Can cause:
Pain
Numbness
Feeling of “pins and needles”
Sensation of heat along nerve
Possible causes of dorsal nerve root compression:
Trauma
Degenerative disc diseases
Herniated Disc
Bulging Disc

9. Ganglion Nerve Cell Cluster
Located in the PNS (outside the brain/spinal cord)
Involved in transmission of sensory information

10. Pia Mater
The delicate innermost membrane of the meninges, enveloping the brain and spinal cord
Thin fibrous tissue
Impermeable to fluid
Allows the enclosure of cerebrospinal fluid
Helps to protect and cushion the brain
When pia mater becomes inflamed, result = meningitis

11. Arachnoid Membrane
One of the 3 meninges that helps protect the brain & spinal cord
The “middle” meninges
Tiny fibers extend of the Arachnoid membrane and attach to pia mater
Resembles spider web (hence it’s name)
Because the brain produces more cerebrospinal fluid (CFS) than the body uses each day, the discarded CFS escapes the subarachnoid space through the arachnoid granulations (tiny protrusions of the arachnoid mater)

12. Dura Mater Outermost membrane enveloping the brain & spinal cord Thick
Responsible for keeping in CFS
Surrounds and supports Dural sinuses and carries blood from brain towards heart
2 layers
Lamellae – superficial layer that serves as skull’s inner periosteum
Meningeal layer – deep layer; the actual Dura mater

13. http://medical-dictionary. thefreedictionary