Abstract
It is proposed that the response of the organism to injury by mechanical energy is made up of three consecutive phases: an immediate or nervous phase, an intermediate or immune phase and a late or endocrine phase. The functions that characterize each one of these three phases could represent the activity of the functional nervous, immune and endocrine systems. This functional concept of the psycho-neuro-immune-endocrine system could make it possible to integrate biochemical knowledge into the organism response to injury.