Chapter 1: Anatomy and Physiology

Question 1

What is p100

Answer 1

a positive waveform that is recorded from the occipital region after a visual stimulus, usually occurs 100ms after the stim

Question 2

What is wave I

Answer 2

“Wave I” refers to a high-frequency (around 600 Hz) repetitive discharge of corticospinal fibers elicited by single-pulse stimulation of the motor cortex

Question 3

What is P13/P14

Answer 3

a complex of positive far-field potentials recorded on the scalp after median nerve stimulation, generated in the caudal brainstem

Question 4

What is N34

Answer 4

subcortically generated far-field potential. It is recorded referentially from an Fpz electrode after posterior tibial nerve stim, it thought to reflect postsynaptic
activity from multiple generator sources in brainstem and perhaps thalamus

Question 5

What is P31

Answer 5

P31 is a positive wave that follows a negative wave (N34) and is thought to reflect brainstem activity after posterior tibial nerve stim, specifically in the dorsal column nuclei and/or caudal medial lemniscus within the lower medulla

Question 6

Which of these cause for a slower nerve conduction velocity?
Larger/Small nerve diameter
Longer/shorter nerve length
low/high transmembrance capacitance
low/high transmembrance resistance

Answer 6

small
no effect
high
low

myelin inc velocity, and causes low capacitance and high resistance

Question 7

Which ion contributes the most to depolariazation, repolarization, and maintaining the resting membrane potential?

Answer 7

Na
K
Cl

Question 8

What determines the flow of ions across a channel?

Answer 8

chemical, electrial gradients as well as membrane conductance

Question 9

What type of nerve fibers contribute most to the conduction velocity measured in NCS?

Answer 9

fast conducting nerve fibers

fast, slow, intermediate and demyelinated fibers all contribute to the amplitude and duration measurements, but not the velocity.

Question 10

effect of limb temperature on conduction velocity and latency?

Answer 10

Inc temp increases velocity and dec latency

Question 11

APB innervation and roots

Answer 11

Median C8-T1

Question 12

Which of the following is most readily recorded as EEG activity with scalp electrodes?

Answer 12

deeper layers 2-6, level 1 is more tangential and better read on MEG

Question 13

WHich of the following describes the absolute refractory period?

Answer 13

Inactivation of Na channels