For more information, log on to- http://shomusbiology.weebly.com/ Download the study materials here- http://shomusbiology.weebly.com/bio-materials.html Human homeostasis is derived from the Greek, homeo or "constant", and stasis or "stable" and means remaining stable or remaining the same.[1] The human body manages a multitude of highly complex interactions to maintain balance or return systems to functioning within a normal range. These interactions within the body facilitate compensatory changes supportive of physical and psychological functioning. This process is essential to the survival of the person and to our species. The liver, the kidneys, and the brain (hypothalamus, the autonomic nervous system and the endocrine system[2]) help maintain homeostasis. The liver is responsible for metabolizing toxic substances and maintaining carbohydrate metabolism. The kidneys are responsible for regulating blood water levels, re-absorption of substances into the blood, maintenance of salt and iron levels in the blood, regulation of blood pH, and excretion of urea and other wastes. An inability to maintain homeostasis may lead to death or a disease, a condition known as homeostatic imbalance. For instance, heart failure may occur when negative feedback mechanisms become overwhelmed and destructive positive feedback mechanisms take over.[3] Other diseases which result from a homeostatic imbalance include diabetes, dehydration, hypoglycemia, hyperglycemia, gout and any disease caused by the presence of a toxin in the bloodstream. Medical intervention can help restore homeostasis and possibly prevent permanent damage to the organs. Humans are warm-blooded, maintaining a near-constant body temperature. Thermoregulation is an important aspect of human homeostasis. Heat is mainly produced by the liver and muscle contractions. Humans have been able to adapt to a great diversity of climates, including hot humid and hot arid. High temperatures pose serious stresses for the human body, placing it in great danger of injury or even death. In order to deal with these climatic conditions, humans have developed physiologic and cultural modes of adaptation. Temperature may enter a circle of positive feedback, when temperature reaches mes of 45°C (113°F), at which cellular proteins denature, causing the active site in proteins to change, thus causing metabolism stop and ultimately death. Energy balance is the homeostasis of energy in living systems. It is measured with the following equation: Energy intake = internal heat produced + external work + storage. When calculating energy balances in the body, energy is often measured in calories, with the definitions of a calorie falling into two classes: The small calorie or gram calorie (symbol: cal)[4] approximates the energy needed to increase the temperature of 1 gram of water by 1 °C. This is about 4.2 joules. The large calorie, kilogram calorie, dietary calorie or food calorie (symbol: Cal)[4] approximates the energy needed to increase the temperature of 1 kilogram of water by 1 °C. This is exactly 1,000 small calories or about 4.2 kilojoules. Source of the article published in description is Wikipedia. I am sharing their material. Copyright by original content developers of Wikipedia. Link- http://en.wikipedia.org/wiki/Main_Page PPT source: All the PowerPoint material is from Sciencegeek.net. Copyright by sciencegeek.net. Link- http://www.sciencegeek.net/Biology/Powerpoints.shtml