Resting membrane potential ( RMP )
1. What is resting membrane potential ( RMP )
2. Explain how RMP is maintained across a typical nerve cell membrane
Answer
1.
Potential ( Voltage ) difference across the cell membrane when cells not producing action potential
2.
When cells are at resting membrane potential , inside the cell is negatively charge and out side positively charge.To keep this differences following conditions must be there
- Unequal distribution of ions of one or more species across the cell membrane ( concentration gradient )
- Permeability of membrane to one or more ion species
Unequal distribution of ions of one or more species across the cell membrane ( concentration gradient )
The concentration of K+ is much higher inside than outside the cell. The Na+ concentration higher out side the cell . This difference is maintain by the Na+-K+ ATPase pump
Permeability of membrane to one or more ion species
Ions cross the cell membrane via channels and pores and these channels permeable to single species of irons. K+ ions passively go out of cell via open K+-selective channels and results outward concentration gradient. similarly Na+ enter into cell through selective Na+ and results inward concentration gradient for Na+. More K+go out of cell than Na+ entering into cell because of opening of more K+channels. Continuous ion leakage doesn't occur it is prevented by the Na+-K+ ATPase pump
More question
Describe the factors contributing to the resting membrane potential generated in a nerve fibre.
Labels: Excitable tissue, Excitable tissue MCQs, Excitable tissue SEQs, Physiology SEQ