After receiving a stimulus, the send(s) signals to the appropriate area of the body.
sensory receptors
integrating center
effectors

Answer;

- Sensory receptors

After receiving a stimulus, the sensory receptors send(s) signals to the appropriate area of the body.

Explanation;

-Sensory receptors are structures that reacts to a physical stimulus in the environment, whether internal or external. They are sensory nerve endings that receives information and conducts a process of generating nerve impulses to be transmitted to the brain for interpretation and perception.

-The sensory receptors include those for tactile sensations, such as touch, pain, and temperature, as well as those for vision, hearing, smell, and taste.