Homeostasis in Organisms

Introduction to Homeostasis

• Homeostasis maintains internal constant environments despite external changes.

• Key processes: regulation of body temperature, blood glucose, and water balance.

Regulation Mechanisms

• Stimulus-Response Model:

  • Consists of stages: Stimulus, Receptor, Control Centre, Effector, Response.

• Feedback Loops:

  • Negative Feedback Loop: Regulates variables by opposing the initial stimulus.

  • Positive Feedback Loop: Enhances the initial stimulus, as seen in childbirth.

Homeostasis in Animals and Plants

• Key variables in regulation: Temperature, Blood glucose, Water balance.

• Vascular plants regulate water through stomata, managing transpiration and gas exchange.

Disorders of Homeostasis

• Type 1 Diabetes: Autoimmune destruction of insulin-producing beta cells, affecting blood glucose regulation.

• Hypoglycaemia: Low blood glucose levels caused by insufficient intake, excess insulin, or strenuous exercise.

• Hyperthyroidism (Graves’ disease): Overproduction of thyroid hormones due to autoantibodies activating the production process without negative feedback control.

Importance of Homeostasis

• Critical for survival; ensures efficient cellular function, glucose regulation, temperature maintenance, and water balance.

• Failure in homeostasis can lead to serious health issues, emphasizing its necessity in physiological processes.