If your blood glucose level for this screening is higher than 200 mg/dL, most practitioners will consider you diabetic and you won't be required to take the glucose tolerance test. But any score between 140 and 200 means that you'll have to take the three-hour glucose tolerance test for a definite diagnosis.
The purpose of homeostasis is to maintain a normal balance within the body regarding its temperature, salt concentration, water concentration, and food intake. The human body functions normally with a narrow range of variation for each of these factors.
This is an ongoing process that continually works to restore and maintain homeostasis. For example, in regulating body temperature there are temperature receptors in the skin, which communicate information to the brain, which is the control center, and the effector is our blood vessels and sweat glands in our skin.