Here's a general overview of how information travels through your body from a stimulus to a reaction:
1. Stimulus: A stimulus is any physical or chemical change in the environment that activates a sensory receptor in your body. Examples of stimuli include light, sound, touch, taste, and smell.
2. Sensory receptors: Sensory receptors are specialized cells that detect stimuli and convert them into electrical signals that can be transmitted to the nervous system. Each type of sensory receptor is specialized to respond to a specific type of stimulus.
3. Sensory neurons: Sensory neurons are nerve cells that transmit electrical signals from sensory receptors to the spinal cord or brain. The sensory neurons are part of the peripheral nervous system.
4. Spinal cord or brain: Depending on the type of stimulus and where it occurs in the body, the electrical signals from sensory neurons may travel directly to the spinal cord or to the brain. The spinal cord is the main pathway for signals that don't require conscious awareness, such as reflexes, while the brain processes signals that require conscious perception.
5. Processing: Once the electrical signals reach the spinal cord or brain, they are processed by a network of neurons that interprets the information and generates a response. This processing may involve multiple regions of the brain, depending on the complexity of the stimulus and the required response.
6. Motor neurons: Motor neurons are nerve cells that transmit electrical signals from the brain or spinal cord to muscles or glands. Motor neurons are part of the peripheral nervous system.
7. Response: The electrical signals from motor neurons cause muscles to contract or glands to secrete hormones or other substances, producing a physical response to the stimulus. This response may be immediate, as in the case of a reflex, or it may be delayed, as in the case of a conscious decision to move or speak.
Overall, the path of information from a stimulus to a reaction involves a complex interplay between sensory receptors, sensory neurons, the spinal cord and brain, motor neurons, and muscles or glands. Each step in this process is critical to the overall response to the stimulus, and any disruptions or damage to these systems can result in a range of sensory and motor deficits.