Final answer:
Interneurons are located only in the central nervous system (CNS), which includes the brain and spinal cord. They are a crucial part of the neural circuits in gray matter. The axon of a neuron travels to the spinal cord to form synapses and transmit signals to other neurons, with efferent nerves in the PNS carrying signals to muscles.
Step-by-step explanation:
Interneurons are specialized neurons that play a crucial role in the processing of information within the central nervous system (CNS). They are found throughout the CNS, which includes both the brain and the spinal cord. To specifically answer the student's question, interneurons are found C) only in the CNS. This encompasses the brain, where they form complex networks that underlie various brain functions, and the spinal cord, where they are involved in reflexes and the processing of sensory and motor information.
Interneurons are primarily located in the gray matter of the CNS. This gray matter makes up the inner parts of the brain responsible for processing signals and the butterfly-shaped region in the center of the spinal cord. The dendrites and synapses of interneurons are significant for transmitting signals, with the synapses facilitating communication between neurons, allowing the CNS to perform its intricate functions.
Neuron A specifically would have its axon traveling to the spinal cord to form a synapse with neuron B. At this synapse, chemical neurotransmitters transmit the signal from neuron A to neuron B. Neuron A is part of the CNS since it is making a connection within the spinal cord, while the axon of neuron B, as part of a nerve traveling to the skeletal muscle, is part of the peripheral nervous system (PNS). This nerve is efferent, as it is carrying signals away from the CNS to elicit a response in the muscle.