Homeostasis

Study Notes

Homeostasis is the process of maintaining a stable internal environment in the body, crucial for proper functioning and survival.

• Central Nervous System (CNS) — consists of the brain and spinal cord, controlling actions and processing information.
  Example: The brain regulates consciousness and movement.
• Peripheral Nervous System (PNS) — includes all nerves outside the CNS, connecting it to the rest of the body.
  Example: Sensory neurons in the skin detect touch and send signals to the CNS.
• Homeostasis — maintenance of a constant internal environment.
  Example: Regulating body temperature to ensure enzyme function.
• Negative Feedback — a mechanism that counteracts changes in the body to maintain balance.
  Example: Insulin and glucagon regulate blood glucose levels.
• Thermoregulation — control of body temperature through mechanisms like sweating and vasodilation.
  Example: Sweating cools the body when it's too hot.
• Osmoregulation — regulation of water and salt concentrations in the body.
  Example: Kidneys adjust urine concentration to maintain water balance.

Exam Tips

Key Definitions to Remember

• Homeostasis: Maintenance of a constant internal environment.
• Negative Feedback: A process that returns conditions to a set point.
• Thermoregulation: Control of body temperature.
• Osmoregulation: Regulation of water and salt balance.

Common Confusions

• Confusing CNS with PNS functions.
• Misunderstanding negative feedback as positive feedback.

Typical Exam Questions

• What is homeostasis?
  Maintenance of a constant internal environment.
• How does negative feedback work?
  It counteracts changes to maintain balance.
• What role do kidneys play in osmoregulation?
  They adjust urine concentration to regulate water balance.

What Examiners Usually Test

• Understanding of homeostasis and its importance.
• Examples of negative feedback mechanisms.
• Differences between CNS and PNS.