Osmoregulation in Biology

The act of maintaining the water and salt balance (osmotic balance) across semipermeable membranes in the body fluids, which are made up of water as well as electrolytes and non-electrolytes, is known as osmoregulation. An electrolyte is a solute that separates into ions when dissolved in water. In contrast, a non-electrolyte does not split into ions during the dissolving of water. The osmotic equilibrium is influenced by electrolytes and nonelectrolytes alike. 

When a cell is immersed in plain water, it tends to swell as water diffuses in from the hypotonic or “low salt” solution. In contrast, a cell shrivels when placed in a solution of high salt concentration. When a cell is kept in hypertonic solutions, the cell loses water as water moves out from the cell as water concentration is more inside the cell as compared to the outer cell environment. When a cell is kept in an isotonic cell, concentration of solutes inside and outside the cell is same, this equalizes the osmotic pressure on either side of the semi-permeable membrane.

Need of osmoregulation:

In complex organisms, exchange of water and nutrients with the environment occurs by consuming food and water and by removing waste from the body in the form of sweat, urine and feces. At the time injury or or certain diseases, toxic waste can be accumulated in the body.

By controlling the quantities of electrolytes present in the three main fluids that are blood plasma, extracellular fluid, and intracellular fluid, mammalian systems have developed to control osmotic pressure. The volume of these fluid compartments may fluctuate as a result of water movement caused by osmotic pressure across membranes. Osmotic pressure can directly affect blood pressure and other medical indications because blood plasma has a fluid component. Therefore osmoregulation is very important as it balances the water and salt in the body.

FAQs

Q1. What is meant by osmoregulation in biology?

Ans 1. Osmoregulation is the biological process by which an organism maintains an internal equilibrium between water and dissolved substances regardless of the external environment.

Q2. Why is there a need for osmoregulation in the body?

Ans2. In complex organisms, exchange of water and nutrients with the environment occurs by consuming food and water and by removing waste from the body in the form of sweat, urine and feces. Therefore, osmoregulation is a very important process to maintain water and salt balance along with the waste removal from the body.