What are the three main functions of the nervous system?

The three main functions of the nervous system are sensory input, information processing, and motor output. This triad describes how the nervous system operates in a coordinated manner.

1. Sensory input refers to the gathering of information from the environment through sensory receptors. These receptors detect changes (stimuli) and send signals to the central nervous system (CNS), where the information can be processed.

2. Information processing occurs in the CNS, which consists of the brain and spinal cord. Here, sensory information is integrated and interpreted, allowing the organism to understand the environment and make decisions based on the input received.

3. Motor output involves the response to processed information. After analysis and decision-making, the CNS sends signals through peripheral nerves to effectors such as muscles or glands, resulting in actions or responses.

This framework is fundamental to understanding how the nervous system maintains communication within the body and facilitates responses to internal and external stimuli. In contrast, the other options focus on functions that do not encapsulate the primary roles of the nervous system.