Sodium ions (Na+) are attracted to the inside of neurons at rest by two forces. The high concentration of (Na+) outside the cell pushes this ion into the cell down the concentration gradient. Likewise, the electrostatic pressure due to the negative charge within the neuron attracts the positively charged (Na+) inside.
Q. What are the three factors that contribute to the resting membrane potential?
Membrane potentials in cells are determined primarily by three factors: 1) the concentration of ions on the inside and outside of the cell; 2) the permeability of the cell membrane to those ions (i.e., ion conductance) through specific ion channels; and 3) by the activity of electrogenic pumps (e.g., Na+/K+-ATPase and …
Table of Contents
- Q. What are the three factors that contribute to the resting membrane potential?
- Q. What contributes to a polarized membrane?
- Q. What happens when potassium moves out of the cell?
- Q. Which part of the neuron initiates the action potential?
- Q. What is action potential conduction?
- Q. Why is it called action potential?
Q. What contributes to a polarized membrane?
Whether or not a membrane is polarized is determined by the distribution of dissociable protons and permeant ions inside and outside the membrane that travel passively through ion channel or actively via ion pump, creating an action potential. …
Q. What happens when potassium moves out of the cell?
Potassium is one of the main blood minerals, or electrolytes, essential to both cellular and electrical function. When potassium leaves the cell, it restores repolarization to the cell, which allows the nerve impulse to progress.
Q. Which part of the neuron initiates the action potential?
axons
Q. What is action potential conduction?
During conduction of an action potential, the passive spread of depolarization to the adjacent distal region of membrane slightly depolarizes the new region, causing opening of a few voltage-gated Na+ channels and an increase in Na+ influx. The action potential is at its peak.
Q. Why is it called action potential?
It is called the action potential because the positive charge then flows through the cytoplasm, activating sodium channels along the entire length of the nerve fibre. The neuron is either at rest with a polarized membrane, or it is conducting a nerve impulse at reverse polarization.
