Fiche de révision : Animal and Plant Hormones in Homeostasis

📋 Course Outline

1. Animal homeostasis and hormones
2. Plant hormones

📖 1. Animal homeostasis and hormones

🔑 Key Concepts & Definitions

• Thermoregulation : Thermoregulation is the set of body processes that keeps internal temperature within a safe range when conditions are too hot or too cold.
• Hormone-secreting glands : Hormone-secreting glands are organs that release hormones into the body, with specific hormones produced and secreted by specific glands.
• Antidiuretic hormone ADH : Antidiuretic hormone (ADH) is a hormone that affects the kidneys’ handling of water, changing urine volume and concentration.

📝 Essential Points

• Homeostasis includes thermoregulation, which corrects disturbances when the environment is too hot or too cold.
• Blood glucose is regulated by hormones to keep levels stable.
• The menstrual cycle is a hormonally driven process used for reproductive-system homeostasis.
• ADH alters kidney function by changing urine volume and urine concentration.

💡 Memory Hook

ADH = “holds” water: less urine volume, more concentrated urine.

📖 2. Plant hormones

🔑 Key Concepts & Definitions

• Plant hormones : Plant hormones are chemical messengers that coordinate growth, development, and responses to the environment.

⚠️ Common Pitfalls & Confusions

1. Mixing up ADH’s effect so you predict higher urine volume when ADH is high.
2. Confusing menstrual-cycle hormone control with blood-glucose regulation.
3. Assuming thermoregulation depends only on skin changes rather than internal homeostatic control.
4. Thinking plant hormones act only like animal hormones without any plant-specific roles.
5. Believing all glands secrete the same hormones rather than specific hormones from specific locations.

✅ Exam Checklist

1. Explain how thermoregulation contributes to animal homeostasis when it is too hot or too cold.
2. Identify that specific hormone-secreting glands are located in specific places and secrete specific hormones.
3. Describe how hormones control blood glucose to maintain stable internal conditions.
4. Outline the menstrual cycle as a hormonally controlled process.
5. State how kidney function is affected by ADH, including the direction of change in urine volume and urine concentration.
6. List plant hormones as key regulators of plant homeostasis and responses.