Lumbosacral meninges, spinal cord and nerve roots dissected from behind
Dura mater in lumbar region
The laminae of the third, fourth and fifth lumbar vertebrae and of the upper two sacral segments have been resected. Epidural fat has been removed to expose segmentally arranges veins (15). Several fibrous strands (10) pass from the lower part of the dura to the sacrum as part of the anchoring mechanism of the meninges.
Lateral cutaneous branch of dorsal branch thoracic nerve XII
Spinous process vertebra L. II
Inferior articular process vertebra L. II
Longissimus thoracis muscle
Iliocostalis muscle
Thoracolumbar fascia
Multifidus muscle (cut across near origin from mammillary process)
Superficial fascia
Dura mater
Fibrous strands attaching dura to sacrum
Gluteus maximus muscle
Fascia of latissimus dorsi muscle
Aponeurosis of latissimus dorsi muscle
Layer of fascia beneath thoracolumbar fascia
Posterior internal vertebral venous plexus
Laminal arch of vertebra L. III (cut across)
Laminal arch of vertebra L. IV (cut across)
Laminal arch of vertebra L. V (cut across)
Laminal arch of sacrum (cut across)
Sacral nerve I
Dural filum terminale (coccygeal nerve roots accompany this band)