The Interaction Function: Perception, Processing, and Response

The Interaction Function

The interaction function enables people to perceive changes and stimuli that occur both inside their bodies and their environment, to interpret or process them and generate coordinated responses in order to survive.

1.1 Perceiving Stimuli

The interaction function can be divided into 3 stages: perception of stimuli, processing of the information and generation of responses.

A stimulus is a physical or chemical change that takes place outside or inside the body and triggers a response in it.

Our bodies contain specialist cells, called receptors, which perceive stimuli and send the information they detect to the coordination centres.

Types of Receptors

• Internal receptors perceive changes inside the body, such as a rise in blood sugar levels. They are spread all over the body and provide information about its general state.
• External or sensory receptors perceive stimuli in the external environment. Depending on the nature of the stimuli they perceive, receptors are classed as:
  • Mechanoreceptors, perceive mechanical stimuli such as pressure, vibration or movement.
  • Thermoreceptors, perceive changes in temperature.
  • Chemoreceptors, detect chemical substances in the air, water, etc.
  • Nociceptors, perceive pain.
  • Photoreceptors, are light-sensitive.

1.2 Processing Information

The coordination centres receive the information sent by the receptors, process it, generate orders and send them to the effector organs. The coordination centres are the nervous system and the endocrine system.

The Nervous System

Responsible for analyzing the internal and external stimuli perceived by receptors, generating orders and sending them to the effectors. It carries out these functions through nerve impulses, which are a kind of electrical current that is transmitted between the neurons.

The nervous system coordinates fast, short-lived responses, such as muscle coordination.

The Endocrine System

Made up of a series of endocrine glands, glands that release the substances into the bloodstream. These substances are called hormones. Coordinate the internal organs by triggering chemical reactions. This system coordinates responses that are slower but longer-lasting.

1.3 Responses

Effectors are the organs responsible for executing the body's response. They include muscles, respond by contracting, and endocrine glands, which respond by secreting substances.