01-31-2014, 06:55 PM
MBME 3 Q.
During an experimental study of the mechanisms of nerve conduction, a researcher isolates a nerve and uses a microelectrode to measure its membrane potential distal to a site of electrical stimulation. The resting potential of the nerve is found to be - 90 mV. The following membrane potentials are then recorded at various points in time after stimulation:
Time After Stimulation (msec)......... Membrane Potential
---- 0 -------------------------------------- -90 mV
---- 0.5 ----------------------------------- +25 mV
---- 1 ------------------------------------- -100 mV
---- 2 ------------------------------------- -90 mV
The change in membrane potential from the resting potential occurring between 0.5 and 1 milliseconds is most likely caused by increased permeability to which of the following ions?
A. Ca2+
B. Cl-
C. K+
D. Na+
E. PO4
During an experimental study of the mechanisms of nerve conduction, a researcher isolates a nerve and uses a microelectrode to measure its membrane potential distal to a site of electrical stimulation. The resting potential of the nerve is found to be - 90 mV. The following membrane potentials are then recorded at various points in time after stimulation:
Time After Stimulation (msec)......... Membrane Potential
---- 0 -------------------------------------- -90 mV
---- 0.5 ----------------------------------- +25 mV
---- 1 ------------------------------------- -100 mV
---- 2 ------------------------------------- -90 mV
The change in membrane potential from the resting potential occurring between 0.5 and 1 milliseconds is most likely caused by increased permeability to which of the following ions?
A. Ca2+
B. Cl-
C. K+
D. Na+
E. PO4
