ionic regulation

Ionic regulation is the physiological process by which organisms maintain a stable internal balance of dissolved ions, regardless of their external environment. This is crucial because ions, such as sodium and potassium, play vital roles in cellular functions, including nerve impulses and muscle contractions.123

Within cells, intracellular fluid contains various dissolved ions and molecules, forming the cytoplasm. The cell membrane regulates the passage of these ions between the intracellular and extracellular fluid, creating ion gradients essential for cell and tissue function. For example, the kidney uses ion gradients to filter waste and reabsorb necessary substances.435

While some marine organisms naturally maintain osmotic balance with their surroundings, others must actively manage water and salt levels. This ionic regulation is closely linked to water balance, collectively ensuring the body's internal stability, a state known as homeostasis.13