Explain what homeostasis is in the body and describe one

Question

1. Explain what homeostasis is in the body, and describe one example in your own word of how your body maintains homeostasis. Be specific. 
2. Choose one of the human body systems (digestive, circulatory, nervous, muscular, endocrine, and immune) and describe in detail what the major functions of this human body system are. Use your own words!
3. Specify which nutrients (macro and micro) affect the health of this particular system overall, and explain what the role of the nutrient is in this body system.
4. How could a lack in any specific nutrient affect this body system? Provide examples, symptoms. 
5. Choose one of the disorders discussed (GERD, IBS, Celiac Disease, or Food Allergies), and briefly explain how this disorder affects your overall health.