How many spinal segments are there?
31
Where does the spinal cord end in comparison to the spine?
The cord ends around the level of the L1/L2 vertebrae
What are the roots that hang down below the L2 vertebrae called?
Cauda Equina
What anchors the spinal cord at the bottom?
filum terminale - an extension of the pia mater
How many cervical segments do we have?
8
How many thoracic *segments *do we have?
12
How many lumbar segments do we have?
5
How many sacral and coccygeal segments do we have?
5 sacral, 1 coccygeal
What is the end of the spinal cord called?
Conus Medullaris
Where do cervical nerve roots exit the spine?
Above the associated cervical vertebrae
exception: C8 exits below C7, between C7/T1
Where do thoracic and lumbar nerve roots exit the spine?
Below the associated vertebrae
Where is the cervical enlargement of the spine?
Between C5 and T1
Where do nerves from the cervical enlargement primarily project to?
Arms
Where is the lumbosacral enlargement of the spine?
Between L1 and S3
Where do nerves from the lumbosacral enlargement primarily project to?
Legs
What type of matter is highly concentrated in the higher regions of the spinal cord?
White matter (descending tracts)
What type of matter is highly concentrated in the lower regions of the spinal cord?
Gray matter (ascending tracts)
Define a myotome
All of the muscles innervated by a single spinal cord segment
What areas do the cervical nerves project to?
Head, neck, arms, diaphragm
What areas do the thoracic nerves project to?
Chest and abdominal muscles
What areas do the lumbar nerves project to?
the more proximal leg muscles
What areas do the sacral nerves project to?
bowel, bladder, distal muscles of the legs
Myotome C5
What muscle(s) is/are implicated?
Deltoid
Myotomes C5/C6
What muscle(s) is/are implicated?
Elbow Flexors
i.e. biceps brachii, brachialis
