Spinal Cord Flashcards
What helps protect the Spinal Cord?
The SC within the Spinal Canal of the vertebral column.
CSF and Meninges provide extra protection.
What are the 3 different Meningeal layers that protect the brain and Spinal cord?
Outer dura layer, middle Arachnoid matter, Inner Pia matter.
When does Elongation of the Spinal cord end?
Stopping around ages 4-5, but growth of the vertebral column continues.
Does the spinal cord go the entire length of the adult vertebral column?
Nope.
What are the 2 main enlargements of the Spinal Column?
Superior and Inferior, Cervical and Lumbar.
What does the Cervical Enlargement of the Spinal column consist of?
Extends from C4 - T1, nn’s to and from arise from cervicle enlargment.
What does the Lumbar Enlargement consist of?
Extends from T9 - T12, nn’s to and from lower limbs arise from lumbar enlargement.
What is the “Conus Medullaris”?
Inferior to the Lumbar Enlargement, the SC terminates as a tapering conical structure called the “Conus Medullaris” Which ends at the level of the Disc between L1-L2.
What arises from the Conus Medullaris?
The “Filum Terminale”.
What is the Function of the Filum Terminale?
An extension of Pia matter that extends inferiorly, fuses with the arachnoid matter and Dura matter.
(Anchors the SC to the Coccyx).
What are Spinal Nerves?
They’re the Paths of communications between the Spinal cord and specific regions of the body.
How many pairs of Cervical Nn’s are there?
There are 8 pairs (C1-C8).
How many pairs of Thoracic Nn’s are there?
There are 12 pairs (T1-T12).
How many pairs of Lumbar Nn’s are there?
There are 5 pairs (L1-L5).
How many pairs of Coccygeal Nn’s are there?
There is 1 pair of Coccygeal nn’s (Co1).
When Axons leave the SC what are they?
They leave the SC as Rootlets.
What is a Rootlet?
There are Ventral & Dorsal Rootlets.
Ventral Rootlets, …
Dorsal Rootlets, …
What does the anatomy of the SC consist of?
White matter, grey matter, Dorsal horn & Ventral Horn.
What Surrounds the inner core or Grey matter in the SC?
White matter.
What are the 2 Grooves that penetrate the White matter of the SC & divide it into Right and left Sides?
The Anterior Median Groove & The Posterior Median Sulcus.
What is the Anterior median Groove?
This is a wide groove on the Anterior (Ventral) side.
What is the Posterior Median Sulcus?
This is a Narrow furrow on the Posterior (Dorsal) side.
What is the Grey Commissure?
This forms the Crossbar of the H in the cross section of the SC.
Where is the Central Canal located?
A small space in the centre of the Grey Commissure.
It extends the entire length of the SC and is filled with CSF.
What does the Posterior (Dorsal) Grey horns contain?
They contain “incoming sensory neurons”.
What does the Anterior (Ventral) Grey horns contain?
They contain “Somatic Motor Nuclei”.
Where are the Lateral Grey Horns located?
They are found between the Anterior and Posterior Grey horns.
Present only in Thoracic and Upper Lumbar SC.
The white matter is organized into regions, What are they?
Anterior (Ventral) White columns, Posterior (Dorsal) White columns & Lateral White columns.
What does each column of white matter consist of?
They each contain distinct bundles of Axons having common origin or destination and carrying similar info.
What are nn bundles that Extend over long distances?
They would be called “Tracts”.
What is Sensory (Ascending) Tracts?
They consist of Axons that conduct nn impulses toward the brain.
What are Motor (Descending) Tracts?
They consist of Axons that carry nn impulses from the brain.
Sensory and motor tracts of the SC are continues with those of the brain.
What happens to a Spinal Nerve after passing though the Intervertebral Foreman?
It decides into several branches.
These branches are known as RAMI.
What is the Posterior (Dorsal) Ramus?
Serves the Deep mm and Skin of the posterior surface of the trunk.
What is the Anterior (Ventral) Ramus?
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