We are hungry and eat, because our body warns us that we are lacking in nutrients. We are thirsty and drinking because we are dehydrating and our bodies need water to function properly. Our pulse and breathing quicken in the face of an extremely activating situation and then we calm down, as we stop being exposed to the situation that requires energy use.
If we look at all of these relationships, we can see that in each of them we are faced with a process that seeks maintain a balance in our body.
This balance is necessary for the proper functioning of our body, so we go through different processes to achieve it. We are talking about body homeostasis, Which we will talk about throughout this article.
What is body homeostasis?
By bodily homeostasis we mean the body’s tendency to actively and constantly seek a state of equilibrium, so that the cells in our body can survive maintaining a stable internal composition.
Maintaining this balance is essential, as activating or sustaining different bodily processes requires energy, which in turn needs elements to be used as fuel. Failure to comply with this instruction will result in a series of tissue damage that can lead to death. The same happens if we are not able to activate or stop some of the aforementioned bodily processes, which are necessary for our survival.
It is important to note that homeostasis works on the basis of the existence of changes that can occur both inside the body and outside, also using mechanisms of action that link the two environments (for example, hunger makes us eat).
The concept of bodily homeostasis, developed by Bernard but named by CannonHe does not tell us about a situation in which the body remains unchanged in a position where there are always the same parameters, but rather about a dynamic balance between states which allows the values of the different components of our body to remain relatively stable. , thanks to various biological mechanisms prepared for this purpose.
In this sense, it should be borne in mind that living things can resist certain levels of variation and imbalance and that the mechanisms that allow homeostasis they can be damaged or changed throughout the life cycleIt is important to keep this in mind in order to introduce external factors that correct any deficits.
For homeostasis to exist, the existence of three basic elements is necessary.
First of all, it is necessary to have some kind of element that acts as a sensor, a receiver that allows that the organization captures existing levels in the parameter or element that must remain in balance.
Secondly there must be some sort of control, A trigger that manages to make it necessary when certain levels are reached.
Third and finally, it is essential that there is some sort of mechanism to react or act once the control mechanism warns that the value of the variable or factor in question reaches the level of imbalance.
Process for balancing the body
The homeostatic regulation process is complex and there are several mechanisms involved. We can specifically highlight three: two of them are purely biological, while the third is more related to neuronal activity and behavior.
Feedback or negative feedback is probably the most logical mechanism of action that homeostasis seems to have and is the easiest to observe and understand.
This mechanism is based on the fact that given the detection of a certain level of a specific parameter which deviates from the normal values, a response is made which seeks returns this parameter to the previous stability.
Examples of this are those provided in the introduction to this article. It is also necessary to keep in mind that it is not a question of a search for balance which intervenes only in situations where there is a lack, but also when there is an excess of something.
For example, in case of changes in body water levelsThirst can occur if the body detects a deficiency or the need to urinate if there is an excess.
Another of the processes necessary to maintain bodily homeostasis may, in fact, seem counterintuitive. This is positive feedback, characterized by increased amplification of unbalanced stimuli, accelerating changes.
This process can be risky and even dangerous for survival, but if it causes the body to move even further away from what it would initially do than the balanced basal state, it has its uses: it may be necessary. to move the basal state to a more optimal situation to survive or to achieve a long-term return to initial situations.
Examples are given in the clotting of blood in the face of an injury, which becomes faster and faster and makes it easier to stop a bleeding.
Feedback means that when a specific signal arrives the body generates some kind of action that allows it to react to the existence of variations.
But this is not the only way to maintain homeostasis: It is also possible to anticipate the arrival of changes and prevent them from occurring. This is the system that would be known as anteroalimentación, and at the biological level we have found it more related to conduct and the capacity of association, as well as instinctive acts.
5 homeostatic processes that occur in our body
We have talked about body homeostasis as a general thing that may seem a bit abstract to most readers (although several examples have been given).
But there are many aspects and functions of our body that need to be regulated to allow our survival. In order to make homeostasis much more visual, let’s look at five other examples (in addition to hunger, thirst, pulse, and cardiorespiratory rhythm or blood clotting already seen) of elements that are regulated and allow the proper functioning of our system.
1. Cell metabolism
Cell metabolism is without a doubt the process that requires the most regulation to keep us alive. And is that our cells are very delicate and must be in a very specific environment.
They need the levels of different elements and ion elements such as sodiumPotassium or calcium, as well as the levels of intracellular fluid and extracellular fluid, are properly regulated so that cells can perform their functions and stay alive.
2. Body temperature
Another bodily mechanism that is continuously regulated is the internal body temperature. The proper functioning of our tissues and organs it may be affected by excessive cold or heat, To the point of being able to lead us to death by hypothermia or hyperthermia.
Fortunately, our body is able to maintain the temperature through a homeostatic process in which, in case of excessive internal temperature, the body reacts with a decrease in physical activity, discomfort and sweating (the goal is to reduce the temperature) or with an increase in activity, generation of tremors, consumption of calories, Blood sampling from secondary areas to direct it to vital areas and search for heat in case of insufficient temperature.
3. Autonomous nervous system
Another clear example of homeostasis is the functioning of the autonomic nervous system.
The sympathetic system allows the body to prepare for action and fight or flight reactions to survive, generating a much higher energy consumption to be able to perform the necessary actions, while the parasympathetic system allows us to reduce activity and activation in order to replenish energies or avoid energetic waste.
An example of deregulation this would occur in chronic stress problems, In which the sympathetic system would be excessively activated continuously.
4. Glucose regulation
In this case, our body acts in such a way that it allows the sugar to be transformed into fat and stored thanks to the insulin, while when it becomes necessary for the body to use glucose, we secrete glucagon to turn fat into sugar. The clearest example of deregulation is given in diabetes.
5. Hormonal regulation
too much endocrine functioning it needs to be regulated. In fact, many of the behaviors that lead to external homeostasis, such as hunger or thirst, sexual desire or stress, depend to varying degrees on this system.
A natural and non-pathological example would be found in the female menstrual cycle, As well as in the dysregulation which would initially imply the menopause.
- Hardy, RM (1979). Homeostasis. Biology notebooks. Omega: Barcelona.
- Guyton, AC and Hall, JE (2016). Treatise on medical physiology. 13th ed. Elsevier.
- Garcia, A. (2016). Homeostasis: regulation and control. Autonomous University of the State of Mexico. Medical School.