Which of these correctly describes the distribution of ions...

Which of these correctly describes the distribution of ions on either side of an axon when it is not conducting a nerve signal? a. more sodium ions (Na') outside and more potassium ions $\left(\mathrm{K}^{+}\right)$ inside b. more $\mathrm{K}^{+}$ outside and less $\mathrm{Na}^{+}$ inside c. charged protein outside; $\mathrm{Na}^{+}$ and $\mathrm{K}^{+}$ inside d. $\mathrm{Na}^{+}$ and $\mathrm{K}^{+}$ outside and water only inside e. chloride ions $\left(\mathrm{Cl}^{-}\right)$ on outside and $\mathrm{K}^{+}$ and $\mathrm{Na}^{+}$ on inside.

Which of these correctly describes the distribution of ions on either side of an axon when it is not conducting a nerve signal?
a. more sodium ions (Na') outside and more potassium ions $\left(\mathrm{K}^{+}\right)$ inside
b. more $\mathrm{K}^{+}$ outside and less $\mathrm{Na}^{+}$ inside
c. charged protein outside; $\mathrm{Na}^{+}$ and $\mathrm{K}^{+}$ inside
d. $\mathrm{Na}^{+}$ and $\mathrm{K}^{+}$ outside and water only inside
e. chloride ions $\left(\mathrm{Cl}^{-}\right)$ on outside and $\mathrm{K}^{+}$ and $\mathrm{Na}^{+}$ on inside.

Key Concepts

Resting Membrane Potential

This is the electrical potential difference across a cell’s membrane when the cell is not actively transmitting signals. It arises primarily from the uneven distribution of ions across the membrane and the membrane’s selective permeability, creating a voltage difference between the inside and outside of the neuron.

Ion Distribution

Ion distribution refers to the specific concentration gradients of ions such as sodium (Na+) and potassium (K+) on either side of the neuron's membrane. At rest, there is typically a higher concentration of Na+ outside the cell and a higher concentration of K+ inside the cell, which is critical for the cell’s ability to generate and propagate electrical signals.

Sodium-Potassium Pump

The sodium-potassium pump is an essential active transport mechanism that maintains the ion concentration gradients across the cell membrane by moving three Na+ ions out of the neuron and two K+ ions into the neuron. This pump is vital for sustaining the resting membrane potential and preparing the neuron for action potential generation.

Selective Permeability

Selective permeability refers to the cell membrane's ability to allow certain ions to pass through more easily than others. In neurons, the membrane is more permeable to potassium ions than to sodium ions at rest, which helps maintain the negative internal environment relative to the outside and is fundamental in establishing the resting membrane potential.

Transcript

Please give Ace some feedback