Spinal Cord And Spinal Nerves

Question 1

Something unique to remember about the cervical nerves

Answer 1

C1-C8 (even though there are only 7 cervical vertebra)

Question 2

What is located at the cervical enlargement?

Lumbosacral enlargement?

Answer 2

Source of brachial plexus (upper limb innervation) C5-T1

Lumbar/sacral plexes (lower limb innervation) L1-S3

Question 3

Spinal cord cell bodies end inferiorly at _____?

Spinal nerves continue inferiorly forming ____

Answer 3

Conus medullaris

Cauda equina

~pia mater extends to form the filum terminale

Question 4

Where are the nerves located in respect to the structures they innervate?

Answer 4

Cell bodies for spinal nerves are at a higher vertebral level than the structures they innervate (so spinal nerves work on cell bodies that are superior to them)

Question 5

Location of a spinal tap? Why?

Answer 5

You draw CSF in the inferior lumbar region because there is no spinal cord there

Question 6

~Look at spinal cord features note and identify

What does 1 contain?

What emerges from 4 and 5?

Answer 6

1. Anterior median fissure (anterior vessels)
2. Posterior intermediate sulcus
3. Posterior median sulcus
4. Posterolateral sulcus (dorsal rootlets emerge)
5. Anterolateral sulcus (ventral rootlets emerge)

Question 7

Butterfly like part of spinal cord is white matter or gray matter?

Answer 7

Gray (neuron cell bodies)

~ white is myelinated axons

Question 8

Gray matter (butterfly part) has 3 horns. What are they and general function

Answer 8

Posterior (dorsal) horn - afferent/sensory

Anterior (ventral) horn - efferent/motor

Lateral column - autonomic efferent; T1-L2 intermediolateral column (sympathetics) S2-4 (parasympathetics)

Question 9

White matter has three tracts - name them and general function overall

Answer 9

Posterior (dorsal) tract (funiculus)
Anterior (ventral) tract (funiculus)
Lateral tract (fasciculus)

Convey ascending and descending axons that communicate with the brain

Question 10

Why is there 8 cervical spinal nerves and 7 cervical vertebra?

Answer 10

C1 spinal nerve emerges ABOVE C1 vertebra (C8 emerges above T1)

Question 11

Basic pathway of spinal nerves

Answer 11

Root (either dorsal or ventral), mixed spinal nerve, rami (dorsal or ventral)

Sympathetics: sympathetic ganglion, rami communicates

Question 12

Dorsal root cell bodies are located?

Somatic motor axons (motor to striated, voluntary muscles) cell bodies are located?

Autonomic motor cell bodies are located?

Answer 12

In dorsal root ganglion

In anterior horn

In lateral horn

Question 13

Name a difference between roots and rami

Answer 13

Roots only have one of the two functional types (sensory/motor); rami contain both

Question 14

Dorsal rami runs sensory and motor fibers to?

Ventral?

Answer 14

To epaxial muscles and skin on the back

To hypaxial muscles and skin on the rest of the body (so these are elaborated into limbs)

Question 15

What connects arachnoid mater to dura mater?

Answer 15

Denticulate ligaments

Question 16

Arteries and veins of spinal cord?

Location?

Answer 16

Right and left posterior spinal arteries, anterior spinal artery; anterior and posterior spinal vein. Venous plexus

All located in subarachnoid space
Except venous plexus which is located in the epidural space