Homeostasis and Automatic Control Systems

Introduction

• Objective: By the end of the session, understand homeostasis and examples, and describe features of automatic control systems in the body.
• Key Idea: Cells and enzymes require stable conditions to function effectively.
  • Enzymes can't work well under changing conditions.
  • Homeostasis maintains these stable conditions.

Homeostasis

• Definition: Regulation of internal conditions of a cell or organism to maintain optimal conditions for function in response to internal and external changes.
• Purpose: Keeps internal conditions as constant as possible.

Importance in the Body

• Example: Endurance athletes
  • Exercise affects body by lowering blood glucose, raising temperature, and causing water loss through sweating.
• Functions: Keeps blood glucose concentration, body temperature, and water levels constant.

Automatic Control Systems

• Role in Homeostasis: Ensure internal conditions stay constant.

General Features

• Can involve the nervous system or hormones.
• Components:
  1. Receptor Cells
     • Detect changes in the environment (internal or external conditions).
     • Stimulus: Any change in the environment.
  2. Coordination Center
     • Receives/processes information from receptor cells.
     • Examples: Brain, spinal cord, pancreas.
  3. Effector
     • Muscle or gland that carries out the response to restore optimum levels.

Summary

• Each system involves a stimulus, receptor, Coordination Center, effector, and response.

Additional Resources

• Practice questions available in the revision workbook.

This lecture provides a foundational understanding of homeostasis and the mechanisms that maintain stable internal conditions through automatic control systems in the body. Focus on grasping the components and their roles in responding to internal and external stimuli to maintain homeostasis.