Explain how an increase or decrease in the permeability (i. e. opening or closing channels permeable) to k+, na+, ca2+, or cl- would change the membrane potential from rest.

An increase or decrease in the permeability of a cell membrane by opening or closing of ion channels would change the membrane potential of a cell membrane from resting membrane potential.

Explanation:

The Resting membrane potential (RMP) normally sits between -50 and -75. This RMP value depends upon the type of ion channels that are open and the concentration of different ions (K+, Na+, Ca2+, Cl-) in the intracellular and extracellular fluids.

For example, in a neuronal cell at a resting state Potassium (K) and Organic anions are found at a higher concentration within the cell than outside. Whereas, Sodium (Na) and Chloride (Cl-) ions are in higher concentration outside the cell. This difference in concentration provides a gradient for ions to flow down their concentration gradient when channels are open as a result of action potential. During depolarization, voltage gated Na+ ions open because of an electrical stimulus. As sodium ions rushes in the cell, the charge inside the cell raises from Negative to Positive changing the Resting Membrane Potential.

Once the cell has been depolarized , the voltage gated Na+ channels close. The raised positive charge inside the cell now causes K+ channels to open, potassium ions now move down the concentration gradient out of the cell so that membrane potential falls and starts to approach the Resting Membrane Potential. This is called re polarization.

So, that's how permeability or opening and closing of ion channels would change the Resting Membrane Potential (RMP).

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step-by-step explanation:

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia