Osmoregulation

Definition

Osmoregulation is the process by which organisms maintain the balance of water and salts in their bodies to ensure proper cellular function. It involves various mechanisms to control osmotic pressure, preventing either excessive uptake or loss of water.

5 Must Know Facts For Your Next Test

1. Osmoregulation is crucial for maintaining homeostasis, particularly in aquatic and terrestrial environments.
2. Key organs involved in osmoregulation include kidneys in mammals, gills in fish, and malpighian tubules in insects.
3. Freshwater fish constantly excrete dilute urine to combat water influx, while marine fish drink seawater and excrete concentrated urine to prevent dehydration.
4. Hormones like antidiuretic hormone (ADH) regulate water balance by increasing water reabsorption in kidneys.
5. Plants use osmoregulation mechanisms such as opening and closing of stomata to manage water loss and uptake.

Review Questions

• What role do kidneys play in osmoregulation?
• How do freshwater and marine fish differ in their osmoregulatory strategies?
• Which hormone is primarily responsible for regulating water balance in mammals?

Related terms

Homeostasis: The maintenance of a stable internal environment within an organism.

Antidiuretic Hormone (ADH): A hormone that helps regulate water balance by increasing the permeability of kidney tubules to water.

Stomata: Pores on plant leaves that control gas exchange and water loss through transpiration.