Biomedical Engineering Reference
In-Depth Information
Table 2.1:
Ion
Intracellular (mM) Extracellular (mM)
Permeability
[
K
+
]
280
10
0.001
[
Na
+
]
51
485
1
[
Cl
−
]
46
340
0.5
a) Report the Nernst potential for each ion.
b) Compute the resting potential.
c) Report the direction that each ionic current moves at rest.
(4) Perform the derivation from Eqs. (2.34) and (2.35).
(5) Below is a strength-duration curve for a membrane with a threshold 7
mV
above rest.
35
30
25
20
15
10
5
0
0
1
2
3
4
5
Duration (msec)
Given the figure, answer the following questions.
a) If a stimulus is above the curve, will the membrane behave linearly or nonlinearly?
b) What is
I
rhe
?
c) What is
R
m
in
kcm
2
?
d) What is
T
ch
in msec?
e) What is
τ
m
in msec?
in
μF /cm
2
?
f ) What is
C
m
1
μF /cm
2
,
R
m
=
3
kcm
2
,
V
rest
m
(6) Draw Strength Duration curve given
C
m
=
=−
60
mV
and
V
th
=−
50
mV
. Be sure to label
I
rhe
and
T
c
and report numerical values for each.
(7) Given that a negative stimulus of -15.7pA applied at t=1msec produced the following:
