Vital functions refer to the necessary functions performed by every living being to maintain life. Even single-celled living beings can also perform vital functions, since the only existing cell can perform them independently.
There are three major vital functions: nutrition, reproduction and relationship with the environment.
Great vital functions
Nutrition collects all the activities that living beings perform to obtain the matter and energy essential for life. Nutrition consists of several factors:
– Food: The survival of living beings is only possible with the ingestion of foods that provide the proteins and nutrients necessary for their development. There are two types of nutrition: heterotrophic and autotrophic. The first is used by humans and animals and is based on the manufacture of matter from organic matter. That is, foods are digested and reduced to simple molecules. The digestive system is fundamental, with digestion, which is a chemical and mechanical process in which there is a breakdown of nutrient molecules, such as lipids, proteins, carbohydrates and nucleic acids.
The second type of nutrition is used by vegetables and consists of creating organic matter from inorganic matter, through photosynthesis.
– Circulation: Circulation is essential for matter to reach all parts of the body. Circulation is done through blood tissue and blood circulates through vessels, arteries, veins and capillaries. Human circulation is double, closed and complete.
– Excretion: Excretion is the elimination of metabolic waste resulting from chemical reactions in the body’s cells. These residues, such as ammonia, urea and uric acid, cannot remain in the bloodstream because they are toxic. In the case of humans and animals, waste is eliminated through urine and faeces, thanks to the excretory system.
– Breathing: Breathing is inserted in nutrition as it is the metabolic process that allows to elaborate and maintain the energy that we obtain through food. It is represented by the processes of inspiration (oxygen entering the body) and expiration (expelling carbon dioxide). The respiratory system is formed by the airways through the lungs.
Reproduction is the vital function that guarantees the survival of the species by passing on genes to future generations. There are two types of reproduction: sexual and asexual. Sexual reproduction is that which requires two individuals of the opposite sex and is performed by the union of the sexual cells (eggs and sperm), or gametes, of each individual, which is called fertilization. Asexual reproduction is that of single-celled beings, in which only one individual intervenes.
Relationship with the environment
It allows living beings to perceive changes in the environment, both internal and external, and to develop responses to these stimuli. In this way, the relationship of living beings with each other and with the environment and the guarantee of survival becomes possible.