From audio: Voltage and Concentration Gradients: 1&2

These flashcards cover key concepts related to the physiology of voltage and concentration gradients, focusing on ion transport mechanisms, driving forces, and physiological conditions affecting membrane potential.

What are the primary physiological forces involved in movement across cell membranes?

Electrical and chemical forces.

What is the pump leak concept in cellular transport?

The simultaneous but independent operation of pumps and leak channels in moving solutes across the plasma membrane.

What does the term 'electrochemical driving force' refer to?

The sum of electrical and chemical forces acting on an ion.

How does the sodium-potassium ATPase function?

It pumps three sodium ions out of the cell and two potassium ions into the cell, fueled by ATP.

What is the equilibrium potential for potassium ion based on concentration gradients?

Approximately -100 millivolts.

What type of channel allows potassium ions to leak through the plasma membrane?

Leak channels.

What causes voltage differences across the cell membrane?

The movement of charged ions across the membrane creates an electrical gradient.

How do changes in ion permeability affect membrane potential?

They can modify the resting membrane potential of the cell.

What is hyperkalemia?

Excessive potassium in blood plasma.

What physiological condition can lead to hyperkalemia (or vice-versa?

Metabolic acidosis.

What effect does rhabdomyolysis have on potassium levels?

It releases intracellular potassium into the plasma, leading to hyperkalemia.

What is the resting membrane potential primarily attributed to in most cells?

The electrochemical equilibrium potential for potassium ions.

Why does the sodium ion channel contribute less to resting membrane potential than potassium?

Sodium channels are less permeable compared to potassium channels.

What three factors influence the electrochemical equilibrium potential for an ion?

Concentration gradient, permeability of the membrane, and electrical gradient.

What is the effect of insulin on potassium levels in the context of hyperkalemia?

It enhances the uptake of potassium into cells by stimulating sodium-potassium ATPase activity.