I. Spinal Cord and Meninges

Use the information on the following pages and in Dr. Stewart's lecture notes on the nervous system to become familiar with the following terms. Sometimes the lecture schedule does not correlate well with what is going on in dissection. It might be useful for you to go ahead and read Dr. Stewart's notes now, even though the lecture is a few weeks away.

Spinal Cord

There are a few important things you need to notice about the diagram below:

1. The are 8 cervical nerves, but only 7 cervical vertebrae. Therefore cervical nerves C1-C7 exit over their corresponding vertebrae, but the remainder of the nerves exit below their corresponding vertebrae. Cervical nerve 8 has no corresponding vertebrae.
2. The spinal cord is shorter than the vertebral column. Spinal roots need to travel caudally to leave the vertebral canal.
3. The spinal cord ends at L2.

• Ridiculously Simple, pg 128, fig 12-5

Spinal Meninges

The spinal meninges are three membranes which surround, support, and protect the spinal cord and cauda equina. The meninges are composed of the dura, arachnoid, and pia mater. The diagrams below iilustrate the relatiomnship between the meninges and the spinal cord.

1. dura mater- tough, outer layer
2. arachnoid mater- spidery intermediate layer
3. pia mater- innermost layer which adheres closely to the surface of the spinal cord

• Baby Moore, pg 212, fig 5.5