Regulation

Regulating Blood Glucose

• If blood glucose is too low, it can cause coma or death.
• If blood glucose is too high, it damages kidneys, nerves, and blood vessels.
• Insulin lowers blood glucose levels if they get too high.
• It is produced by the 'Islets of Langerhans' in the pancreas.

Regulating pH

• Blood pH must be maintained at 7.4.
• High CO₂ levels lower pH. To restore balance:
  • Breathing rate increases to expel CO₂.
  • Kidneys excrete H⁺ ions.
• The medulla oblongata in the brain detects increased CO₂ levels and signals an increase in the breathing rate, which expels CO₂.

Regulating Calcium Levels

• Calcium is needed for muscular contraction and healthy bones and teeth.
• If calcium levels are too low, the parathyroid glands release parathormone.
• Parathormone increases calcium levels in the blood.

Regulating Water and Salt Concentration

• The kidneys and brain work together to control water and salt levels in the body.
• In plants, stomata retain water when soil water levels are low.