A Stable Internal Environment : Homeostasis Essay

1804 Words Dec 13th, 2016 8 Pages
The human body is composed of eleven major systems that all work together to hold a stable internal environment: homeostasis. Each system consists of different organs that all play important roles in maintaining homeostasis. The circulatory, respiratory and renal systems greatly affect each other in the keeping of the internal environment. Homeostasis is defined as the tendency of an organism or a cell to regulate its internal conditions, usually by a system of feedback controls, so as to stabilize health and functioning, regardless of outside changing conditions. In other words, humans are able to maintain a constant internal environment despite the change in external conditions. For example, people maintain an internal temperature of about 98.6 degrees Fahrenheit even when the weather outside may be much colder or warmer. People do this by shivering to produce heat in the cold and sweating to cool off in the warmth. The process of maintaining these internal conditions is called negative feedback or positive feedback. The negative feedback loop allows the body to maintain its internal state by doing opposite of what is happening in the body. For example, if blood glucose levels rise, the pancreas makes and secretes insulin into the blood stream to effectively lower blood glucose in order to maintain homeostasis. The opposite of a negative feedback loop is a positive feedback loop. Instead of the body reducing the effect of a stimulus it enhances it. A great example of…

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