The nervous system has three overlapping functions; sensory input, integration, and motor output.; it is a highly integrative system and is capable of adapting to external influences

Sensory input comes from the many sensory receptors that monitor changes occurring both inside and outside the body. The total sum of the information gathered by these receptors is called sensory input. The nervous system processes and interprets sensory input and decides what actions should be taken. The nervous system activates effector organs such as muscles and glands to cause a response called motor output.

At the integrative level, the primary function of the nervous system is the high-level control and integration of body systems as well as the adaptive capability to external influences. It does this by extracting information from the environment using sensory receptors. This sensory input is sent to the central nervous system, which determines an appropriate response. 

Once the response is activated, the nervous system sends signals via motor output to muscles or glands to initiate the reaction.

Key Points

• The nervous system is highly integrated and is capable of adapting to external influences. It has three overlapping functions based on sensory input, integration, and motor output.

• At a more integrative level, the primary function of the nervous system is to control and communicate information throughout the body.

Key Terms

hormone: a molecule released by a cell or a gland in one part of the body that sends out messages affecting cells in other parts of the organism.

nervous system: the organ system that coordinates the activities of muscles, monitors organs, constructs, and processes data received from the senses, and initiates actions.

sensory input: describes the response in a sensory organ when it receives stimuli

receptors: are proteins which bind to ligands and cause responses in the body

effector organ: are a muscle or gland that contracts or secretes in direct response to nerve impulses