Anatomy of the Spinal Cord and Spinal Nerves Flashcards
Where is the spinal cord located?
In the vertebral canal of the vertebral column.
What is the structure of the spinal cord?
Central core of gay matter (neuron cell bodies etc.) and surrounding white matter (axons etc.)
How many pairs of spinal nerves are there and what are they?
31 pairs. 8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
What is each spinal nerve formed from?
The union of anterior (central) root and posterior (dorsal) root
What does each spinal nerve divide into?
Anterior ramus and posterior ramus.
Where does the spinal cord begin?
Begins at foramen magnum at base of skull (continuous with medulla of brainstem), travels from vertebral levels C1 to L1/L2 in adults (L3 in infants).
What is conus medullaris?
The tapered inferior end of the spinal cord.
How are spinal nerves names?
named according to their exit point from the spine - intervertebral foramen or anterior and posterior sacral foramen.
Where do cervical spinal nerves exit from?
Exit above corresponding pedicle.
Where do throacic and lumbar spinal nerves exit from?
Below corresponding pedicle.
Where do sacral spinal nerves exit from?
Rami exit via sacral foramina (S1-4) or sacral hiatus
Where are nerve roots located?
In the vertebral canal.
What is the cauda equine?
The nerve roots inferior to cord.
What are the meninges of the spinal cord?
Pia - innermost layer, attached to surface of spinal cord.
Arachnoid - middle layer
Dura - outermost layer, thickest.
Subarachnoid space
Between pia and arachnoid, filled with cerebrospinal fluid (CSF); brain and spinal cord floats in CSF
Subdural space
Between dura and arachnoid, potential space
Epidural space
Between dura and vertebrae, contains fat and blood vessels (but in cranial cavity, a potential space)