PhysioEx 3 Activities 1-9 RLansu.docx - Rebekah Lansu...

Rebekah Lansu PhysioEx #3 Activities 1-9
BIO 201IN 20392
PhysioEx Lab Report
Exercise 3: Neurophysiology of Nerve Impulses Activity
1: The Resting Membrane
Potential Name: Rebekah Lansu
Date: 11 April 2021
Session ID: session-fd943ef6-f32d-e4db-8040-
bae1b64c84e2
Pre-lab Quiz Results
You scored 100% by answering 4 out of 4 questions correctly.

1 What is the approximate concentration of K
+
inside a typical cell
(intracellular concentration)?

2 What is the approximate concentration of K
+
outside a cell (extracellular
concentration)?

3 What is the approximate concentration of Na
+
inside a cell (intracellular
concentration)?

4 What is the approximate concentration of Na
+
outside a cell
(extracellular concentration)?
Experiment Results
Predict Question
1 Predict Question: Predict what will happen to the resting membrane potential if
the extracellular K
+
concentration is increased.
Stop & Think Questions
1 What is the polarity of the resting membrane potential (voltage)?


2 What does it mean that the voltage just inside the membrane is
negative?
3 The membrane of most cells, including neurons, contains passive, open,

K
+
leak channels. Given the normal K
+
concentrations and the resultant
concentration gradient, which direction would K
+
be expected to move
(diffuse) through these leak channels?

4 What effect does increasing extracellular K
+
have on the net diffusion of
K
+
out of the cell?
5 Which way would Na move across the membrane if there were open

+
Na
+

6 The membrane has open K
+
channels, and changing extracellular K
concentration results in a change in membrane potential. Changing the
extracellular Na
+
concentration does not significantly change the
membrane potential. What do your results suggest about the number or
state (open or closed) of Na
+
channels in the resting membrane of a
neuron?
+
Experiment Data
Post-lab Quiz Results
You scored 100% by answering 3 out of 3 questions correctly.

1 A negative membrane potential was recorded when the tip of the
microelectrode was
You correctly answered: both inside the cell body and inside the
axon.

2 Which of the following caused a change in membrane potential
from -70 to -40 in the cell

body?

3 Which of the following has the most negative voltage?