How the Process of Homeostasis Works

Homeostasis and body temperature
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Homeostasis refers to the body's need to reach and maintain a certain state of equilibrium. The term is often used to refer to the body's tendency to monitor and maintain internal states such as temperature and energy levels at fairly constant and stable levels.

A Closer Look at Homeostasis

The term homeostasis was first coined by a psychologist named Walter Cannon in 1926. The term refers to an organism's ability to regulate various physiological processes to keep internal states steady and balanced.

These processes take place mostly without our conscious awareness.

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 levels drop in your house, 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 kick in until the set point is once again reached.

Homeostasis involves three key features:

1. A clear set point

2. The ability to detect deviations from this set point

3. Behavioral and physiological responses designed to return the body to the set point

Your body has set points for a variety of things including temperature, weight, sleep, thirst, and hunger.

One prominent theory of human motivation, known as drive reduction theory, suggests that homeostatic imbalances create needs. This need to restore balance drives people to perform actions that will return the body to its ideal state.

How Does the Body Regulate Temperature?

When you think about homeostasis, temperature might come to mind first.

It is one of the most important and obvious homeostatic systems. All organisms, from large mammals to tiny bacteria, must maintain an ideal temperature in order to survive. Some factors that influence this ability to maintain a stable body temperature include how these systems are regulated as well as the overall size of the organism.

Some creatures, known as endotherms or "warm-blooded" animals, accomplish this via internal physiological processes. Birds and mammals (including humans) are endotherms. Other creatures are ectotherms (aka "cold blooded") and rely on external sources to regulate their body temperature. Reptiles and amphibians are both ectotherms.

Note, however, that the colloquial terms warm-blooded and cold-blooded do not actually mean that these organisms have different blood temperatures. These terms simply refer to how these creatures maintain their internal body temperatures.

Homeostasis is also influenced by an organism's size, or more specifically, the surface-to-volume ratio.

  Larger creatures have a much greater body volume, which causes them to produce more body heat. Smaller animals, on the other, produce less body heat but also have a higher surface-to-volume ratio. They lose more body heat than they produce, so their internal systems must work much harder to maintain a steady body temperature.

Behavioral and Physiological Responses

As mentioned earlier, 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 heat.

As endotherms, people also possess a number of internal systems that help regulate body temperature. As you probably already know, humans have a body temperature set point of 98.6 degrees Fahrenheit. When your body temperature dips below this point, it sets off a number of physiological reactions to help restore balance. Blood vessels in the body's extremities constrict in order to prevent heat loss. Shivering also helps the body produce more heat.

The body also responds when temperatures go above 98.6 degrees. Have you ever noticed how your skin becomes flushed when you are very warm? This is your body trying to restore temperature balance. When you are too warm, your blood vessels dilate in order to give off more body heat. Perspiration is another common way to reduce body heat, which is why you often end up flushed and sweaty on a very hot day.

Browse the Psychology Dictionary


Frebert, L.A. (2010). Discovering Biological Psychology. Belmont, CA: Wadsworth.

Homeostasis.  (2001). The Corsini Encyclopedia of Psychology and Behavioral Science, Volume 2, Craighead, W.E., & Nemeroff, C.B. (Eds.). New York: John Wiley & Sons.

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