Osmoregulation

Osmoregulation - the control of ==water and salt== concentration

Factors that influence water potential: - Water vapour breathed out - Sweating - Volume of water drunk - Kidneys cause water loss

Controlling water Levels

Pituitary gland releases the ==antidiuretic hormone== which regulates the volume of urine excreted

If hydrated:

• Increase in water in the blood
• Receptors in hypothalamus detect this, pituitary gland produces ==LESS ADH==
• Makes collecting duct LESS permeable to water
• LESS water reabsorbed into the blood
• More dilute urine, pale yellow

If dehydrated:

• Decrease in water in the blood
• Receptors in hypothalamus detect this, pituitary gland produces ==MORE ADH==
• Makes collecting duct ==MORE permeabl==e to water
• MORE water reabsorbed into the blood
• More concentrated urine, dark yellow