Which structures are the primary components of the central nervous system (CNS)?

• A. Cranial nerves and spinal nerves
• B. Brain and spinal cord
• C. Sympathetic chain ganglia and adrenal medulla
• D. Skeletal muscles and sensory receptors

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the definition of the central nervous system (CNS). The CNS consists of the main control centers of the nervous system responsible for processing and integrating information.
2. Step 2: Identify the primary structures that make up the CNS. These are the brain and the spinal cord, which together coordinate sensory input and motor output.
3. Step 3: Differentiate the CNS from the peripheral nervous system (PNS). The PNS includes cranial nerves, spinal nerves, sympathetic chain ganglia, and other structures outside the brain and spinal cord.
4. Step 4: Recognize that cranial nerves and spinal nerves are part of the PNS, not the CNS, as they connect the CNS to limbs and organs.
5. Step 5: Conclude that the correct answer is the brain and spinal cord, as these are the primary components of the central nervous system.