What is the temperature in the room where you’re in right now? My guess would be that it’s not exactly 37 degrees, Yet, your body temperature is usually near this value. In fact, if your core body temperature doesn’t stay within these narrow range(from 35 to 41)the results can be dangerous or even deadly.
Homeostasis refers to the body’s constant struggle to reach and maintain a certain state of normalcy. The term is often used to refer to the body’s tendency to observe and keep internal states such as temperature and energy levels at fairly constant and stable levels.
These processes take place subconsciously.
Our internal regulatory systems have what is known as a set point for a variety of things. This is much like the thermostat in your house or the A/C system in your car. Once set at a certain point, these systems work to keep the internal states at these levels.
When the temperature drops in your apartment, your furnace will turn on and warm things up to the preset temperature. In the same way, if something is out of balance in your body, a variety of physiological reactions will start until the set point is once again achieved.
Homeostasis happens in different aspects, not just the level of the whole body as it is for temperature. For example, the stomach maintains a pH that’s different from that of surrounding organs, and each individual cell maintains ion concentrations different from those of the surrounding fluid. Maintaining homeostasis at each level is crucial to maintaining the body’s overall function.
homeostasis involves both physiological and behavioral responses.
In terms of behavior, you might seek out warm clothes or a patch of sunlight if you start to feel chilly. When you start to feel chilled, you might also curl your body inward and keep your arms tucked in close to your body to keep in the heat.
maintaining homeostasis usually involves negative feedback loops. These loops act to oppose the stimulus, or cue, that triggers them. For instance, if your body temperature is too high, a negative feedback loop will act to bring it back down towards the set point(37 degrees).
First, high temperature will be detected by sensors—majorly nerve cells with endings in your skin and brain—and relayed to a temperature-regulatory control center in your brain. The control center will process the information and activate effectors—such as the sweat glands—whose job is to oppose the stimulus by bringing body temperature down.
Without a doubt body temperature doesn’t just rise above its target value—it can also drop below this value. In general, homeostatic circuits normally involve at least two negative feedback loops:
- One is activated when a parameter—like body temperature—is abovethe set point and is designed to bring it back down.
- One is activated when the parameter is belowthe set point and is designed to bring it back up.
Diabetes, as an instance, is a disease caused by a broken feedback loop involving the hormone insulin. The broken feedback loop makes it difficult or impossible for the body to bring high blood sugar down to a healthy level.
Some biological systems, by the way, use positive feedback loops. Unlike negative feedback loops, positive feedback loops strengthen the starting signal. Positive feedback loops are usually found in processes that need to be pushed to completion, not when the status quo needs to be maintained.