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7.1. Relationship function and the nervous system

Nervous system and relationship function

As has been seen in this and other previous courses, living beings are characterized by their three vital functions:

  • Nutrition : provides thenecessary matter and energy.
  • Relationship : allows you to detect and obtain information from the internal and external environment to be able to adapt  to these circumstances and to be able to develop the appropriate responses that allow you to survive, eat, find a partner, etc.
  • Reproduction : necessary to ensure the survival of the species.

All living things have these three functions. It is evident that they need the nutrition function, since food helps them to obtain the necessary matter and energy. Also the reproduction function, since if not, the species would disappear. But it is more difficult to understand what the relationship function consists of.

The relationship function enables the body to :

  • Adapt to the changing conditions of the environment, both exterior and interior.
  • Coordinate the different parts of the body.

stimulus is any change that occurs in the external or internal environment of living beings that is capable of causing a response.

The relationship function will be in charge of receiving the stimulus, transmitting it to the nervous centers, elaborating the response and giving the necessary orders for that response to take place. The sensory receptors  (organs of the senses) will be in charge of receiving the information in the form of a stimulus, transmitting it to the nervous system that receives it, processes it, and elaborates a response that can be endocrine, with the intervention of the endocrine system, or nervous, with intervention of the effector organs (skeletal and muscular system).

There are two types of coordination systems in animals:

  • Hormonal coordination: The  endocrine system is made up of glands that secrete hormones into the blood that regulate some actions of the body. Its action is slow and long-lasting. For example, the appearance of secondary sexual characteristics is controlled by hormones.
  • Nervous coordination: The nervous system is responsible for carrying out, through neuronsquick and short-lived responses that allow life to be maintained. For example, when we see food or cross the street we are using our nervous system.

Answer in your notebook

7.1.- Why is hormonal coordination slower and longer than nervous coordination?

Answer in your notebook

7.2.- What is the relationship function for? What systems are involved?