Nerve Fibers, Myelination, Function

Question 1

A alpha fiber
myelination
function
diameter
velocity
block onset

Answer 1

heavy myelination
skeletal motor and proprioception
12-20
+++++
4th

Question 2

a beta fiber
myelination
function
diameter
velocity
block onset

Answer 2

heavy myelination
touch and pressure
5-12
++++
4th

Question 3

a gamma fiber
myelination
function
diameter
velocity
block onset

Answer 3

medium myelination
skeletal muscle tone
3-6
+++
3rd

Question 4

a delta
myelination
function
diameter
velocity
block onset

Answer 4

medium myelination
fast pain, temperature, touch
2-5
+++
3rd

Question 5

b fibers
myelination
function
diameter
velocity
block onset

Answer 5

light myelination
preganglionic ANS fibers
3 diameter
++
1st
(this is what is blocked via spinal)

Question 6

c sympathetic fibers
myelination
function
diameter
velocity
block onset

Answer 6

none
postganglionic ANS fibers
.3-1.3
+
2nd

Question 7

c dorsal root fibers
myelination
function
diameter
velocity
block onset

Answer 7

none
slow pain, temperature, touch
.4-1.2
+
2nd

Question 8

for a spinal anesthetic, the autonomic block will be how many dermatome levels higher than the sensory block?

Answer 8

2-6

Question 9

what is the primary site of action of a spinal anesthetic?

Answer 9

Preganglionic ANS fibers in the subarachnoid space