Full Answer Section

• 1. Thermoregulation: When body temperature rises above the set point, the body initiates cooling mechanisms such as sweating and vasodilation (widening of blood vessels). When body temperature drops below the set point, the body initiates warming mechanisms such as shivering and vasoconstriction (narrowing of blood vessels).  

Positive Feedback Mechanisms

• How they work: These mechanisms amplify the original stimulus, moving the system further away from the starting point. They are less common than negative feedback loops and typically act to complete a specific process.  
• Example:
  1. Childbirth: During labor, the hormone oxytocin stimulates uterine contractions. These contractions, in turn, stimulate the release of more oxytocin, further intensifying contractions. This positive feedback loop continues until the baby is delivered.  

Key Differences:

• Direction of Change: Negative feedback loops oppose the initial change, while positive feedback loops amplify it.  
• Outcome: Negative feedback loops maintain stability and homeostasis, while positive feedback loops often lead to a specific endpoint.  

In Summary:

• Negative feedback mechanisms are crucial for maintaining a stable internal environment by counteracting deviations from the set point.  
• Positive feedback mechanisms are less common but essential for processes that require a rapid and significant change, such as childbirth or blood clotting.