6D - Osmoregulation GLOSSARY

Osmoregulation

Maintaining the balance of water and salts.

Solute

The substance (like salt) dissolved in a liquid.

Solvent

The liquid (usually water) that does the dissolving.

Water

The essential solvent for life.

Diffusion

Movement of particles from high to low concentration.

Osmosis

Movement of water from low solute to high solute concentration.

Tonicity

Ability of a solution to make a cell gain or lose water.

Hypotonic

Solution with a lower solute concentration than the cell.

Isotonic

Solute concentration is equal inside and outside.

Hypertonic

Solution with a higher solute concentration than the cell.

Osmolality

A measure of how concentrated a solution is.

Crenate

When an animal cell shrivels because it lost water.

Blood Pressure

The force of blood against vessel walls.

Pituitary Gland

Gland that releases ADH into the blood.

Kidney Cells

Cells that filter blood and regulate urine.

Collecting Duct

Kidney part where water reabsorption happens.

Reabsorption

Taking water or solutes back into the blood from the kidney.

ADH

Hormone that increases water reabsorption.

Renin & Aldosterone

Hormones that regulate sodium and blood pressure.

Aquaporin

Special channels for water to move through.

Na-K Pump

Active transport pump for Sodium (Na) and Potassium (K).

Sodium

A key solute (ion) that regulates water movement.

Urine Concentration

How 'salty' or 'watery' the urine is.

Thirst Centre

Hypothalamus region that makes you want to drink.