In an introductory anatomy and physiology context, the peripheral nervous system (PNS) consists primarily of which structures?

• A. The brain, spinal cord, and meninges
• B. The sympathetic and parasympathetic nuclei located within the spinal cord gray matter only
• C. The cerebrum, cerebellum, and brainstem
• D. Cranial nerves, spinal nerves, and associated ganglia outside the brain and spinal cord

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the distinction between the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord, while the PNS includes all neural structures outside the CNS.
2. Step 2: Identify the main components of the PNS. These include cranial nerves, spinal nerves, and associated ganglia, which are clusters of neuron cell bodies located outside the brain and spinal cord.
3. Step 3: Recognize that the meninges, cerebrum, cerebellum, brainstem, and nuclei within the spinal cord are parts of the CNS, not the PNS.
4. Step 4: Recall that the sympathetic and parasympathetic nuclei are located within the CNS (specifically in the spinal cord gray matter and brainstem), but their peripheral components (like ganglia and nerves) are part of the PNS.
5. Step 5: Conclude that the PNS primarily consists of cranial nerves, spinal nerves, and associated ganglia outside the brain and spinal cord, which transmit signals between the CNS and the rest of the body.