What are the three vital functions

When we speak of vital functions, we refer to the functions that every living being performs to maintain life. They are made up of a total of three and are common to all, and even unicellular living beings can perform them, since the only cell they have performs them independently. Without them it would be completely impossible to survive and all species would become extinct, since one of them is reproduction. If you want to know what the three vital functions are, keep reading this article and find out.

Vital functions: nutrition

The nutrition is the vital function that allows us to keep us alive, it includes all the activities we do all living beings to obtain essential matter and energy to live. In order to perform properly, nutrition is made up of several factors:

• Feeding. Without the intake of food that provides us with the proteins and nutrients necessary to develop and grow, survival would not be possible. There are two types of nutrition: heterotrophic and autotrophic. The first of them corresponds to that used by humans and animals, and is based on the manufacture of our own material from organic matter. That is, we eat foods that can be both animal and vegetable origin, our body digests them and reduces them to simple molecules. The digestive system plays a fundamental role in this process. While the second consists of the creation of organic matter from inorganic matter, such as carbon dioxide, water or mineral salts, through photosynthesis. Thus, it corresponds to the form of nutrition of vegetables.
• Circulation. This process of nutrition is vital to get the matter to all parts of the body. It is done through the circulatory system, which we explain in detail in this video.
• Excretion. All living beings ingest the matter and energy they need to live and expel substances that are harmful, harmful or useless for them, through the body or photosynthesis, and this is done through excretion. In the case of humans and animals, we do it through urine and fecal matter, thanks to the excretory system.
• Breathing. We include breathing in nutrition because it is the metabolic process that allows us to have, elaborate and maintain all the energy that we have acquired through food. It consists of the entry of oxygen into the body and the expulsion of carbon dioxide through the respiratory system.

Vital functions: reproduction

The play is the vital role that we can ensure the proliferation of species. Without it, we would become extinct and form a planet devoid of life. Through reproduction, living beings can generate organisms similar to themselves and thus achieve the long-term survival of the species to which they belong. There are two main types of reproduction, sexual and asexual.

The sexual reproduction It is the one that requires the intervention of two individuals of the opposite sex, that is, one female and the other male. It is carried out by the union of the sexual cells (ovules and spermetazoids), or gametes, of each of the individuals, which is called fertilization. This union can occur externally, in which the sex cells unite outside the body of individuals and the eggs, therefore, are formed outside (this is the case of many of the marine animals, therefore this type of fertilization is produced in water); or internal, in which the male cells, sperm, must enter the female”s body through the reproductive organs, unite with her gametes, ovules, and fertilize them. Thus, the fetus develops within the body of the female (it occurs in mammalian animals and humans).

The asexual reproduction is one in which only intervene a single individual, characteristic of unicellular organisms. Several types are distinguished within this branch of reproduction:

• Bipartition of a cell into two to give rise to two children, is the case of unicellular algae and protozoa.
• Fragmentation of an organism giving rise to the creation of another living being, in the case of starfish, among others.
• Budding, in which the parent creates a new individual through the buds found in the plasma membrane. The father performs an unequal division of one of his cells, the smallest one passes into the bud and another similar organism develops. This is the case of sea sponges, among others.

Vital functions: relationship

The relationship is the vital function that allows us to react and generate a response or stimulus to a certain change. When we speak of stimulus, we refer to a variation of the environment, while when we say response, we are referring to the reaction of both cells and living beings. In general, it is the stimuli that generate a response, which can be positive, when the movement goes in the same direction, or negative, if it goes in the opposite direction. A clear example of a stimulus can be the feeling of hunger, whose positive response would be the instinct and act of hunting for food.

Thanks to the perception of changes in the environment (stimuli), both internal (of our own body) and external (environment), and the elaboration of responses to these stimuli, it is possible to guarantee survival, since it is what makes it possible for beings to Living relationships with each other and with the environment.