Actually it is Avocado which has 38.1 mEq of potassium compared to a banana which has 11.6 mEq of potassium. Other good choices are Baked Potato 12.9 mEq, Raisins 19.3 mEq, Cantaloupe 12.7 mEq, Dates 13.9 mEq, and Orange Juice with 11.2 mEq. Potassium is also plentiful in the gastrointestinal tract. Potassium is constantly moving in and out of cells according to the body's needs, under the influence of the sodium-potassium pump. Thus, serum potassium values need to be closely monitored.
Potassium influences both skeletal and cardiac muscle activity.
For example, alterations in its concentration change myocardial irritability and rhythm. Alterations in acid-base balance have a significant effect on potassium distribution. Hypokalemia can cause alkalosis and, vice versa, alkalosis can cause hypokalemia. Hyperkalemia can cause acidosis and vice versa, acidosis can cause hyperkalemia. For example, in acidotic states, some of the excess hydrogen ions enter the cells to help correct plasma pH. In so doing, potassium ions are released from the cells in order to maintain electroneutrality.