2. in psychiatry, an unconscious defense mechanism in which unacceptable ideas, fears, and impulses are thrust out or kept out of consciousness. 3. gene r. enzyme repression interference, usually by the endproduct of a pathway, with synthesis of the enzymes of that pathway. gene repression the inhibition of gene transcription of an operon; in prokaryotes repressor binding to the operon is involved.
The ratio of intracellular to extracellular potassium determines neuromuscular and cardiovascular excitability, which is why serum potassium is normally regulated within a narrow range of 3.5 to 5.0 mmol/L. Dietary K+ intake is highly variable, ranging from as low as 40 mmol/day to more than 100 mmol/day.
Describe the movement of sodium and potassium ions across a neuron's membrane during resting potential: there is a slight leakage of sodium ions and potassium ions during resting potential sodium diffuses from outside, where it is higher in concentration, to the inside potassium diffuses in the opposite direction, since it is more concentrated inside the neuron What does the Sodium Potassium ATPase do to the flux of ions across the gradients? the sodium potassium pump maintains concentration gradients for the two ions by pumping sodium out of the cell and potassium back into the cell