16 Introduction to Homeostasis

Homeostasis:

At home there is usually a specific temperature which is considered “comfortable.” If it gets too cold you turn on the heat to bring the temperature up to the ideal, and if gets too hot you might open a window to return to the “sweet spot.” Note how to achieve the “ideal,” “sweet spot,” or “perfect temperature” you have to adjust the air conditioning or open windows.

Similarly, homeostasis refers to the body’s ability to maintain a stable internal environment despite external changes. It is a dynamic process involving constant adjustments that ensure physiological systems remain within narrow, life-sustaining limits. Elements like body temperature, blood pressure, pH levels, and fluid balance are regulated through feedback mechanisms. When these variables deviate from normal ranges, the body activates responses to restore balance, often through the nervous and endocrine systems. The major components of homeostasis follow below:

• • Stimulus: Produces spike in a specific variable
  • Receptor: Collects input from body and sends signals to control center
  • Control centre: Directs the output through signals. Evaluates the severity of receptor signals and acts accordingly
  • Effector: Brings about change in the body

 figure x.  Homeostasis: Reacting to a stimulus to return to equilibrium