Spinal Cord

Where does the spinal cord extend to?

L1/L2

What is the end of the spinal cord called?

Conus medullaris

What is the end of conus medullaris called?

Cauda equina

Where does the cauda equina extend to?

S5

What is the cauda equina?

A collection of dorsal and ventral nerve roots that bind together to form a spinal nerve

Where do the spinal nerve exit?

Intervertebral foramina

What is the dura mater?

The outer tough collagenous tissue that encloses the spinal cord and the cauda equina

Where does the dura mater extend to?

The brain at the foramen magnum down tube of S2

Where is the epidural space?

Between the dura mater and the bony interior of the vertebral canal

Where is the subdural space?

Between the dura mater and the arachnoid mater

What is the arachnoid mater?

It lines the inside of the dural sac and extends as a web through subarachnoid space to attach to the pia mater

Where is the subarachnoid space?

Between arachnoid and pia mater

Where is the cerebrospinal fluid?

In the subarachnoid space

Where is the lumbar cistern?

Between L2 and S2; it is the subarachnoid space that contains the cauda equina and filum internum

Where is cerebrospinal fluid extracted from during a spinal tap?

Through the lumbar cistern from L4 and below

Where is the pia mater?

It is the innermost meningeal covering and bound to the surface of the spinal cord and nerve roots

What are denticulate ligaments?

Lateral projections of the pia mater that form triangular shaped ligaments that extend from the spinal cord to the internal surface of the dura mater

What is contained inside the pia mater?

Filum terminale internum (FTI) inferior to the conus medullaris

How many denticulate ligaments are there?

21 pairs; dorsal roots on the posterior side and ventral roots on the anterior side

Where is the filum terminale externum (FTE)?

At the end of the dural sac and passes through (while gaining a layer of dura), and ocntinues inferiorly and attaches to the coccyx

What is the coccygeal ligament?

The FTE

Why would cervical enlargements of the spinal cord be clinically important?

They might make the patient more susceptible to having compression/impingements in the enlarged area

What do dorsal rami innervate?

Deep intrinsic muscles of the back and skin of posterior head, neck, and trunk

What do ventral rami innervate?

Anterior and lateral trunk, limbs, and neck

Why is there disproportion between the spinal cord and vertebral column growth?

The SC stops growing at age 4 but the vertebral column stops growing at ages 14-18

How many segments are in the spinal cord total and within each region?

31:

8 Cervical

12 thoracic

5 Lumbar

5 Sacral

1 Coccygeal

Which spinal nerve would be affect by a small HNP at L5/S1?

S1 spinal nerve

Which spinal nerve is affected during a small HNP?

The spinal nerve whose number corresponds to the number of the vertebrae below

Where is anesthesia injected during a spinal block?

The subarachnoid space

Where is anesthesia injected during an epidural block?

The epidural space into the sacral canal via sacral hiatus

Which injection site of anesthesia is more common for childbirth?

Epidural block

Where is anesthesia injected during a pudendal nerve block?

Near the ischial spine or around the pudendal nerve