What is the primary difference between afferent and efferent neurons, and what role do interneurons play in the nervous system?

• A. Afferent neurons carry signals away from the central nervous system, efferent neurons carry signals to it, and interneurons transmit signals to muscles.
• B. Afferent neurons carry signals to muscles, efferent neurons carry signals to the central nervous system, and interneurons connect sensory and motor neurons.
• C. Afferent neurons connect neurons within the central nervous system, efferent neurons carry signals to the central nervous system, and interneurons carry signals away from it.
• D. Afferent neurons carry signals to the central nervous system, efferent neurons carry signals away from it, and interneurons connect neurons within the central nervous system.

Answer: (D)

Verified step by step guidance

1. Understand the basic function of neurons in the nervous system: Neurons are specialized cells that transmit information throughout the body. They are categorized into three main types: afferent neurons, efferent neurons, and interneurons.
2. Define afferent neurons: Afferent neurons, also known as sensory neurons, carry sensory information from the peripheral body parts to the central nervous system (CNS). They are responsible for transmitting signals such as touch, pain, temperature, and other sensory inputs to the brain and spinal cord.
3. Define efferent neurons: Efferent neurons, also known as motor neurons, carry signals away from the central nervous system to the peripheral body parts. These signals typically result in muscle contraction or gland secretion, thus enabling movement and other responses.
4. Define interneurons: Interneurons are found within the central nervous system and serve as connectors or relays between afferent and efferent neurons. They play a crucial role in processing information and determining the appropriate response by integrating sensory input with motor output.
5. Summarize the roles: Afferent neurons bring information to the CNS, efferent neurons carry commands from the CNS to the body, and interneurons facilitate communication within the CNS, ensuring that sensory inputs are effectively translated into motor outputs.