What is the general pathway of the nervous system?

What is the general pathway of the nervous system?

• A. Stimulus - receptor - motor neurone - sensory neurone - effector - response
• B. Stimulus - receptor - sensory neurone - relay neurone - motor neurone - effector - response
• C. Receptor - stimulus - sensory neurone - relay neurone - motor neurone - effector - response
• D. Stimulus - receptor - sensory neurone - reflex arc - effector - response

Answer: (B)

Understanding how a signal travels from a stimulus to a response helps you see why this sequence is correct. When a stimulus is detected, receptors pick it up and generate a nerve impulse that moves along a sensory neurone to the central nervous system. In the CNS, the impulse usually passes to a relay (interneuron) that processes the information, then it travels via a motor neurone to an effector such as a muscle or gland, producing the response. This fits the general pathway: stimulus -> receptor -> sensory neurone -> relay neurone -> motor neurone -> effector -> response. The other options misorder steps—for example one puts the motor neurone before the sensory neurone, another starts with the receptor after the stimulus, and another uses a reflex arc as a separate stage rather than the usual CNS relay step. A reflex arc is a specific, often faster pathway that bypasses higher brain centers, but the standard sequence still centers on the same components in the CNS.

Understanding how a signal travels from a stimulus to a response helps you see why this sequence is correct. When a stimulus is detected, receptors pick it up and generate a nerve impulse that moves along a sensory neurone to the central nervous system. In the CNS, the impulse usually passes to a relay (interneuron) that processes the information, then it travels via a motor neurone to an effector such as a muscle or gland, producing the response. This fits the general pathway: stimulus -> receptor -> sensory neurone -> relay neurone -> motor neurone -> effector -> response. The other options misorder steps—for example one puts the motor neurone before the sensory neurone, another starts with the receptor after the stimulus, and another uses a reflex arc as a separate stage rather than the usual CNS relay step. A reflex arc is a specific, often faster pathway that bypasses higher brain centers, but the standard sequence still centers on the same components in the CNS.