7. Resting Cell Membrane Flashcards
1
Q
Membrane potential
A
All cells have electrical potential difference across plasma membrane
Provides basis of signalling in nervous system and many types of cells
2
Q
What is the resting potential in a cardiac myocyte?
A
-80mV
3
Q
What is the resting potential in neurones?
A
-70mV
4
Q
What is the resting potential in skeletal muscle myocytes?
A
-90mV
5
Q
What is the resting potential in smooth muscle myocytes?
A
-50mV
6
Q
Ionic concentrations of extracellular
A
Na+ 145mM
K+ 4.5mM
Cl- 123mM
7
Q
Setting up resting potential
A
K+ channels open
K+ move out down chemical (diffusion) gradient
K+ move in down electrical gradient
When they are equal and opposite, no net movement of K+, negative membrane potential
Membrane selectively permeable to K+
Ek is -95mV
