What determines membrane resistance?

What determines membrane resistance?

The membrane resistance is a function of the number of open ion channels, and the axial resistance is generally a function of the diameter of the axon. The greater the number of open channels, the lower the rm. The greater the diameter of the axon, the lower the ri.

What factors influence an ion’s movement across a membrane?

Two factors determine the net flow of ions across an open ionic channel: the membrane potential and the differences in ion concentrations between the intracellular and the extracellular spaces.

What factors does an ion’s equilibrium potential depend on?

These three factors are (1) the concentration gradients, (2) the valence of the ionic species in question, and (3) temperature. If there is no concentration gradient across the plasma membrane, the ratio of the extracellular to intracellular concentration terms becomes 1.

What are the factors that could affect the ion movement?

Other non-structural factors that can play a vital role, even a dominant role, in enhancing ionic conductivity are charge carrier concentration, ion-ion interactions or bonding characteristics, vibrational amplitudes of neighboring ions, lattice compressibility or resiliency, rotational motion of anions, ion size, etc.

What is the membrane resistance of a neuron?

Neurons have fairly high membrane resistances (∼100–300 MΩs), resting potentials around −70 mV and express a particular complement of voltage-gated sodium (Nav) and potassium (Kv) channels that allow action potential firing upon membrane depolarization (Purves et al., 2001).

What is membrane resistance and capacitance?

A cell’s capacitance determines how quickly the membrane potential can respond to a change in current. A cell’s resistance is a measure of how easily ions can move through the membrane and this concept is more critical to this lab than the issue of capacitance.

What determines the direction of water movement?

the concentration of water determines the direction in which molecules will move during osmosis. the concentration of solute os higher outside the cell than that on the inside, therefore the water concentration outside the cell is higher.

What causes a cell to shrivel?

A hypertonic solution means the environment outside of the cell has more dissolved material than inside of the cell. If a cell is placed in a hypertonic solution, water will leave the cell. This can cause a cell to shrink and shrivel.

What determines the overall resting membrane potential of a cell?

The resting potential is mostly determined by the concentrations of the ions in the fluids on both sides of the cell membrane and the ion transport proteins that are in the cell membrane. In this case, the resting potential of this cell would be the same as the equilibrium potential for potassium.

What determines equilibrium potential?

The value of the equilibrium potential for any ion depends upon the concentration gradient for that ion across the membrane. If the concentrations on the two sides were equal, the force of the concentration gradient would be zero, and the equilibrium potential would also be zero.