The tendency to maintain a relatively constant internal environment
Homeostasis
Typically involves negative feedback loops that counteract changes of various properties from their target values, known as set points
Properties maintained by homeostasis
Temperature
Concentration of various ions in blood
pH
Concentration of glucose
If the values of properties maintained by homeostasis get too high or low, you can end up getting very sick
How homeostasis is maintained
1. When you exercise, your muscles increase heat production, nudging your body temperature upward
2. When you drink a glass of fruit juice, your blood glucose goes up
Negative feedback loops
Act to oppose the stimulus, or cue, that triggers them
How negative feedback loops work
1. If the level of something rises, control systems are switched on to reduce it again
2. If the level of something falls, control systems are switched on to raise it again
Negative feedback mechanisms
Usually a continuous cycle of bringing levels down and then bringing them back up so that overall, they stay within a narrow range of what is considered 'normal'
