6.4.1 Principles of Homeostasis

Key Processes of Homeostasis:

1. Negative Feedback Mechanism:

• Definition: A process that reverses a change in internal conditions to restore optimum levels.
• Components:
• Sensory Receptors detect changes (e.g., temperature or glucose levels).
• Information is transmitted via the nervous or hormonal system.
• Effectors (e.g., liver, muscles) bring about a response to restore normal conditions.
• Example:
• If blood glucose falls, hormones stimulate the conversion of glycogen to glucose, returning glucose levels to normal.

2. Positive Feedback Mechanism:

• Definition: A process that enhances the original change rather than reversing it.
• Example:
• During childbirth, the dilation of the cervix triggers the release of oxytocin, which increases uterine contractions, further dilating the cervix.

Importance of Homeostasis:

• Maintains enzyme activity within optimal ranges.
• Ensures cell function and survival by stabilising internal conditions.
• Regulates critical processes such as blood pH and temperature control.