Lumbosacral meninges, spinal cord and nerve roots dissected from behind

Arachnoid membrane covering cauda equina

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Image #219-6
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Lumbosacral meninges, spinal cord and nerve roots dissected from behind
Arachnoid membrane covering cauda equina
The dura has been removed so that the arachnoid membrane remains intact. The filum terminale (15) appears as a white strand deep to the arachnoid. An extensive subarachnoid space surrounds the nerve roots which form the cauda equina.
1 . Mamillary process vertebra L. III
2 . Inferior articular process vertebra L. II
3 . Iliocostalis muscle
4 . Lamina (arch of vertebra) L. IV
5 . Thoracolumbar fascia
6 . Ligamentum flavum
7 . Epidural space and cut margin of dura
8 . Fibrous attachment of dura to sacrum
9 . Cystic enlargement of dura covering roots of second sacral nerve (note resorption of neighboring bone)
10 . Gluteus maximus muscle
11 . Spinous process vertebra L. II
12 . Branch of lumbar artery
13 . Dura mater
14 . Arachnoid
15 . Filum terminale (beneath arachnoid)
16 . Sacral nerve II
17 . Level at which spinal subarachnoid space terminates
18 . Dural filum terminale