Final answer:
The correct option is 2. Interneurons link sensory stimuli with the appropriate motor responses by connecting sensory neurons to motor neurons and integrating cognitive functions with sensory input to generate reactions.
Step-by-step explanation:
The function of interneurons is to link sensory stimuli with the appropriate motor responses. Interneurons, also known as connector neurons or association neurons, play a critical role in the nervous system by connecting sensory neurons, which relay sensory information from the environment, to motor neurons that execute a response. The integration of sensory input with other sensations, as well as with cognitive functions such as memories, learning, and emotion, is a fundamental aspect of how the nervous system generates an appropriate reaction to various stimuli.
Motor neurons are the nerve cells that carry signals from the central nervous system to the muscles and glands, causing them to act. On the other hand, sensory neurons carry information from sensory receptors towards the central nervous system. Interneurons serve as critical intermediaries, processing the sensory input and determining the right signal to send to the motor neurons, leading to a motor response.
When a sensory neuron detects a stimulus, it sends an impulse along its axon to synapse with an interneuron within the central nervous system. This interneuron then processes the information, which may be combined with cognitive data such as past experiences or emotional states, and passes the appropriate responses to the motor neurons. The motor neurons then send the impulse to the muscles or glands to respond accordingly.
Therefore, the correct option in the final answer is (2) interneurons.