The contents of the vertebral canal

Conus medullaris (L1-L2), filum terminale internum, filum terminale externum

31 pairs of spinal nerves

8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

Spinal nerves - nerve rootlets

• Ventral rootlets - mainly motor fibres

•  Dorsal rootlets - mainly sensory fibres

Dorsal (posterior) rootlets, ventral (anterior) rootlets

Spinal nerves

• Spinal Nerve - Motor and sensory fibres.

•  Boundary between central and peripheral nervous system

Cervical spinale nerves

Cervical spinal nerves exit above tehir corresponding numbered vertebra

Cauda equina

The lumbar, sacral and coccygeal nerve roots descend downwards in the cauda equina

Suppllies of dorsal (posterior) rami

•  Intrinsic back muscles

•  Z-joints of spine

•  Ligaments of spine

•  Skin on posterior head,

  neck, spine and pelvic girdle

ventral (anterior) rami forms…

• Cervical Plexus

• Brachial Plexus

•  Lumbar Plexus

•  Sacral Plexus

•  Intercostal Nerves of

  Trunk

Intercoastal nerves - thoracic region

Each intercostal nerve formed by a single spinal nerve.

Supplies:

• Muscles and skin in

  thoracic wall

• Segmental distributio

Recurrent meningeal nerve

Doubles back into the intervertebral foramen

 Anterior dura and dural sleeves

 The posterior longitudinal ligament

The posterior and posterolateral portions of the intervertebral disc

Rami communications

Connects ventral rami with sympathetic chain of autonomic nervous system

Dura mater

Tough mother

• OUter layer of meninges

The meninges - dural sleeve

• Sleeve like projection from the dura mater

• Covers dorsal and ventral nerve roots until they reach intervertebral foramen

Arachnoid mater

• Thin shiny layer just underneath the dura mater

• Has delicate spider wed like apperance

Pia mater

Skin like layer that covers the spinal cord and brain

Denticulate ligaments

• Triangular thickenings from pia mater to arachnoid and dura mater

• Help to suspend cord within the dural sac