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

• A. The brain and spinal cord only
• B. Only the autonomic nervous system (sympathetic and parasympathetic divisions)
• C. Only sensory receptors located in the skin
• D. Cranial nerves, spinal nerves, and peripheral ganglia (all neural structures outside the brain and spinal cord)

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the basic division of the nervous system into the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS includes the brain and spinal cord, while the PNS includes all neural structures outside the CNS.
2. Step 2: Identify the components of the PNS, which primarily consist of cranial nerves, spinal nerves, and peripheral ganglia. These structures connect the CNS to limbs and organs.
3. Step 3: Recognize that the autonomic nervous system (ANS), which includes sympathetic and parasympathetic divisions, is a functional subdivision of the PNS but not the entirety of it.
4. Step 4: Note that sensory receptors located in the skin are part of the PNS but represent only a subset of its components, specifically related to sensory input.
5. Step 5: Conclude that the PNS is best described as including cranial nerves, spinal nerves, and peripheral ganglia, which encompass all neural structures outside the brain and spinal cord.